Resin produced by polycondensation, and resin composition

ABSTRACT

A polyester carbonate resin is provided, which includes a structural unit derived from a compound represented by general formula (1), a structural unit derived from a compound represented by general formula (2), a structural unit derived from a dicarboxylic acid or a derivative thereof, and a structural unit derived from a carbonic acid diester. The polyester carbonate can be used, e.g., in optical systems.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a Divisional Application of U.S. applicationSer. No. 15/306,638, filed Oct. 25, 2016, which is a National Stage ofInternational Patent Application No. PCT/JP2015/063143, filed May 1,2015, which claims priority to Japanese Application No. 2014-096100,filed May 7, 2014. The disclosure of each of the applications listedabove is incorporated by reference herein in its entirety.

TECHNICAL FIELD

The present invention relates to a resin produced by polycondensation,which comprises a structural unit having a specific binaphthyl skeletonand a structural unit having a specific fluorene structure, and a resincomposition.

BACKGROUND ART

As a material of optical elements to be used in optical systems ofvarious cameras such as cameras, film integrated type cameras and videocameras, an optical glass or an optical transparent resin is used.Optical glasses are excellent in heat resistance, transparency, sizestability, chemical resistance, etc., and there are various opticalglasses with different refractive indexes or Abbe numbers. However,optical glasses have problems of high material costs, bad moldingprocessability and low productivity. In particular, significantlyadvanced techniques and high costs are required for processing forobtaining an aspherical lens to be used for aberration correction, andthis is a major obstacle from a practical viewpoint.

Contrary to the above-described optical glasses, advantageously, opticallenses made of optical transparent resins, particularly thermoplastictransparent resins can be mass-produced by injection molding, and inaddition, an aspherical lens can be easily produced therefrom. Suchoptical lenses are currently used as camera lenses. Examples of opticaltransparent resins include a polycarbonate made of bisphenol A, apolymethyl methacrylate and an amorphous polyolefin.

In general, in optical systems of cameras, aberration is corrected bycombining a plurality of concave lenses and convex lenses. Specifically,chromatic aberration is synthetically corrected by combining convexlenses having chromatic aberration with concave lenses having chromaticaberration whose sign is opposite to that of the chromatic aberration ofthe convex lenses. In this regard, the concave lenses are required tohave high dispersion (i.e., a low Abbe number).

When the above-described optical transparent resins are considered fromthe viewpoint of high dispersion (low Abbe number), the polycarbonatemade of bisphenol A has a refractive index of about 1.59 and an Abbenumber of about 32, the polymethyl methacrylate has a refractive indexof about 1.49 and an Abbe number of about 58, and the amorphouspolyolefin has a refractive index of about 1.54 and an Abbe number ofabout 56. Among them, only the polycarbonate can be used as concavelenses for aberration correction, but when the Abbe number is 32, itcannot be said that sufficiently high dispersion is obtained thereby.For this reason, a novel material which can be used as concave lensesfor aberration correction has been desired.

As a resin to be used for concave lenses for aberration correction,Patent Document 1 discloses a polyester resin composition obtained bycopolymerization of a fluorene-based dihydroxy compound having arefractive index of about 1.66 and an Abbe number of about 20.

Next, birefringence will be described. The polycarbonate resin made ofbisphenol A is widely used for optical lenses, but applications of thepolycarbonate resin are limited because of high birefringence thereof asa drawback. In particular, in applications to cameras for cellularphones and digital cameras, as the resolution has been increasedrecently by the improvement of the pixel number, a resin material havinghigh imaging performance and low birefringence has been desired.

Examples of methods for realizing low birefringence of resin materialsinclude a technique of canceling positive birefringence of a compositionwith negative birefringence of another composition (Patent Document 5).The sign (positive or negative) of birefringence is determined by thedifference between the polarizability of the polymer main chaindirection and the polarizability of the polymer side chain direction.For example, a polycarbonate resin made of bisphenol A in which thepolarizability of the polymer main chain direction is larger than thepolarizability of the polymer side chain direction has positivebirefringence, and a polycarbonate resin made of bisphenol having afluorene structure in which the polarizability of the polymer side chaindirection is larger has negative birefringence. For this reason, thecomponent ratio of materials whose birefringence signs are opposite toeach other is very important. By using a resin having low birefringence,optical distortion is reduced.

Patent Document 6 describes that use of a dicarboxylic acid having afluorene structure as a raw material in a polyester resin is effectivefor reduction of birefringence. Note that carboxylic acid is a type of acompound having a hydroxyl group (Non-Patent Document 1).

Note that polymers having a 1,1′-binaphthalene structure are describedin Patent Documents 2, 3 and 4. However, Patent Documents 2 and 3 do notdisclose any resin having a structural unit derived from a compoundrepresented by general formula (1). Patent Document 4 describes apolymer comprising a structural unit represented by general formula (A),but it is not a polymer comprising a structural unit having a fluorenestructure. Further, the patent document does not disclose whether thesign of birefringence of the polymer comprising a structural unitrepresented by general formula (A) is positive or negative.

(X represents a C₁₋₁₀ alkylene group.)

(In the formula, A represents a C₂₋₄ alkylene group. The naphthalenering may be substituted with a substituent, and substituted substituentsmay be subjected to ring condensation. m and 1 respectively represent aninteger of 0≤m≤50 and an integer of 0≤l≤50.)

CITATION LIST Patent Document

-   Patent Document 1: Japanese Laid-Open Patent Publication No.    2006-335974-   Patent Document 2: Japanese Laid-Open Patent Publication No.    2000-302857-   Patent Document 3: Japanese Laid-Open Patent Publication No.    2001-72872-   Patent Document 4: Japanese Laid-Open Patent Publication No.    2002-332345-   Patent Document 5: International Publication WO2007/142149 pamphlet-   Patent Document 6: Japanese Laid-Open Patent Publication No.    2013-64119

Non-Patent Document

-   Non-Patent Document 1: Renji Okazaki, “Iwanami Lecture Series,    Introduction to Modern Chemistry <9> Characteristics and Molecular    Transform of Organic Compounds”, Iwanami Shoten, 2004, page 96 (in    Japanese)

SUMMARY Technical Problem

The purpose of the present invention is to provide a resin havingexcellent optical characteristics such as a high refractive index and alow Abbe number in view of the above-described problems.

Solution to Problem

The present inventors diligently made researches and found that a resinobtained by using a specific monomer particularly provides opticallysuperior performance, for example, a high refractive index and a lowAbbe number.

Specifically, the present invention is, for example, as follows:

[1] A polyester resin, comprising which comprises:

a structural unit derived from a compound represented by general formula(1) below:

wherein X represents a C₁₋₁₀ alkylene group;

a structural unit derived from a compound represented by general formula(2) below:

wherein R¹ and R² each independently represent a hydrogen atom, a C₁₋₂₀alkyl group, a C₁₋₂₀ alkoxyl group, a C₅₋₂₀ cycloalkyl group, a C₅₋₂₀cycloalkoxyl group, a C₆₋₂₀ aryl group or a C₆₋₂₀ aryloxy group and Rrepresents a hydrogen atom or a C₁₋₂₀ hydroxyalkyl group; and

a structural unit derived from a dicarboxylic acid or a derivativethereof.

[2] The polyester resin according to item [1], wherein the compoundrepresented by general formula (2) is a compound represented by generalformula (2a) below:

wherein R¹ and R² are as defined in item [1], or a compound representedby general formula (2b) below:

wherein R¹ and R² are as defined in item [1].[3] The polyester resin according to item [1] or [2], wherein thedicarboxylic acid or a derivative thereof is naphthalene dicarboxylicacid, terephthalic acid, isophthalic acid, dicarboxylic acid having afluorene group or an ester thereof.[3-1] The polyester resin according to item [3], wherein thedicarboxylic acid having a fluorene group is a dicarboxylic acidrepresented by general formula (3) below:

wherein Ys each independently represent a single bond, a C₁₋₂₀ alkylgroup, a C₁₋₂₀ alkoxyl group, a C₅₋₂₀ cycloalkyl group, a C₅₋₂₀cycloalkoxyl group, a C₆₋₂₀ aryl group or a C₆₋₂₀ aryloxy group.[4] The polyester resin according to any one of items [1] to [3-1],wherein in structural units derived from a dihydroxy compound in thepolyester resin, the ratio of the structural unit derived from thecompound represented by general formula (1) is 5 to 95 mol % and theratio of the structural unit derived from the compound represented bygeneral formula (2) is 2.5 to 47.5 mol %.[5] The polyester resin according to any one of items [1] to [4],further comprising a structural unit derived from glycol, wherein in thestructural units derived from the dihydroxy compound in the polyesterresin, the ratio of the structural unit derived from glycol is 5 to 70mol %.[5-1] A polyester resin obtained by copolymerization of:

a compound represented by general formula (1) below:

wherein X represents a C₁₋₁₀ alkylene group;

a compound represented by general formula (2) below:

wherein R¹ and R² each independently represent a hydrogen atom, a C₁₋₂₀alkyl group, a C₁₋₂₀ alkoxyl group, a C₅₋₂₀ cycloalkyl group, a C₅₋₂₀cycloalkoxyl group, a C₆₋₂₀ aryl group or a C₆₋₂₀ aryloxy group and Rrepresents a hydrogen atom or a C₁₋₂₀ hydroxyalkyl group; and

a dicarboxylic acid or a derivative thereof.

[6] An optical member comprising the polyester resin according to anyone of items [1] to [5-1].

[7] The optical member according to item [6], which is an optical lensof a single-lens reflex camera, a digital still camera, a video camera,a cellular phone with a camera, a disposable camera, a telescope,binoculars, a microscope or a projector.

[8] A polyester carbonate resin, comprising:

a structural unit derived from a compound represented by general formula(1) below:

wherein X represents a C₁₋₁₀ alkylene group;

a structural unit derived from a compound represented by general formula(2) below:

wherein R¹ and R² each independently represent a hydrogen atom, a C₁₋₂₀alkyl group, a C₁₋₂₀ alkoxyl group, a C₅₋₂₀ cycloalkyl group, a C₅₋₂₀cycloalkoxyl group, a C₆₋₂₀ aryl group or a C₆₋₂₀ aryloxy group and Rrepresents a hydrogen atom or a C₁₋₂₀ hydroxyalkyl group;

a structural unit derived from a dicarboxylic acid or a derivativethereof; and

a structural unit derived from a carbonic acid diester.

[9] The polyester carbonate resin according to item [8], wherein thecompound represented by general formula (2) is a compound represented bygeneral formula (2a) below:

wherein R¹ and R² are as defined in item [8], or a compound representedby general formula (2b) below:

wherein R¹ and R² are as defined in item [8].[10] The polyester carbonate resin according to item [8] or [9], whereinthe dicarboxylic acid or a derivative thereof is naphthalenedicarboxylic acid, terephthalic acid, isophthalic acid, dicarboxylicacid having a fluorene group or an ester thereof.[10-1] The polyester carbonate resin according to item [10], wherein thedicarboxylic acid having a fluorene group is a dicarboxylic acidrepresented by general formula (3) below:

wherein Ys each independently represent a single bond, a C₁₋₂₀ alkylgroup, a C₁₋₂₀ alkoxyl group, a C₅₋₂₀ cycloalkyl group, a C₅₋₂₀cycloalkoxyl group, a C₆₋₂₀ aryl group or a C₆₋₂₀ aryloxy group.[10-2] The polyester carbonate resin according to any one of items [8]to [10-1], wherein the carbonic acid diester is selected from the groupconsisting of diphenyl carbonate, ditolyl carbonate, bis(chlorophenyl)carbonate, m-cresyl carbonate, dimethyl carbonate, diethyl carbonate,dibutyl carbonate and dicyclohexyl carbonate.[11] The polyester carbonate resin according to any one of items [8] to[10-2], wherein in structural units derived from a dihydroxy compound inthe polyester carbonate resin, the ratio of the structural unit derivedfrom the compound represented by general formula (1) is 5 to 95 mol %and the ratio of the structural unit derived from the compoundrepresented by general formula (2) is 2.5 to 47.5 mol %.[11-1] A polyester carbonate resin obtained by copolymerization of:

a compound represented by general formula (1) below:

wherein X represents a C₁₋₁₀ alkylene group;

a compound represented by general formula (2) below:

wherein R¹ and R² each independently represent a hydrogen atom, a C₁₋₂₀alkyl group, a C₁₋₂₀ alkoxyl group, a C₅₋₂₀ cycloalkyl group, a C₅₋₂₀cycloalkoxyl group, a C₆₋₂₀ aryl group or a C₆₋₂₀ aryloxy group and Rrepresents a hydrogen atom or a C₁₋₂₀ hydroxyalkyl group;

a carbonic acid diester; and

a dicarboxylic acid or a derivative thereof.

[12] The polyester carbonate resin according to any one of items [8] to[11-1], which has a refractive index of 1.645 to 1.660.

[13] The polyester carbonate resin according to any one of items [8] to[12], which has a polystyrene equivalent weight-average molecular weight(Mw) of 14,000 to 100,000.

[14] An optical member comprising the polyester carbonate resinaccording to any one of items [8] to [13].

[15] The optical member according to item [14], which is an optical lensof a single-lens reflex camera, a digital still camera, a video camera,a cellular phone with a camera, a disposable camera, a telescope,binoculars, a microscope or a projector.

[16] A polycarbonate resin, comprising:

a structural unit derived from a compound represented by general formula(1) below:

wherein X represents a C₁₋₁₀ alkylene group; and

a structural unit derived from a compound represented by general formula(2) below:

wherein R¹ and R² each independently represent a hydrogen atom, a C₁₋₂₀alkyl group, a C₁₋₂₀ alkoxyl group, a C₅₋₂₀ cycloalkyl group, a C₅₋₂₀cycloalkoxyl group, a C₆₋₂₀ aryl group or a C₆₋₂₀ aryloxy group and Rrepresents a hydrogen atom or a C₁₋₂₀ hydroxyalkyl group, thepolycarbonate resin having a phenol content of 0.1 to 3000 ppm.[17] A polycarbonate resin, comprising:

a structural unit derived from a compound represented by general formula(1) below:

wherein X represents a C₁₋₁₀ alkylene group; and

a structural unit derived from a compound represented by general formula(2) below:

wherein R¹ and R² each independently represent a hydrogen atom, a C₁₋₂₀alkyl group, a C₁₋₂₀ alkoxyl group, a C₅₋₂₀ cycloalkyl group, a C₅₋₂₀cycloalkoxyl group, a C₆₋₂₀ aryl group or a C₆₋₂₀ aryloxy group and Rrepresents a hydrogen atom or a C₁₋₂₀ hydroxyalkyl group, thepolycarbonate resin having a carbonic acid diester content of 0.1 to1000 ppm.[18] A resin composition, which comprises:

a polycarbonate resin comprising:

-   -   a structural unit derived from a compound represented by general        formula (1) below:

wherein X represents a C₁₋₁₀ alkylene group; and

-   -   a structural unit derived from a compound represented by general        formula (2) below:

wherein R¹ and R² each independently represent a hydrogen atom, a C₁₋₂₀alkyl group, a C₁₋₂₀ alkoxyl group, a C₅₋₂₀ cycloalkyl group, a C₅₋₂₀cycloalkoxyl group, a C₆₋₂₀ aryl group or a C₆₋₂₀ aryloxy group and Rrepresents a hydrogen atom or a C₁₋₂₀ hydroxyalkyl group; and

an antioxidant; and/or

a mold release agent.

[19] The resin composition according to item [18], wherein theantioxidant is pentaerythritoltetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate].

[20] The resin composition according to item [18] or [19], wherein themold release agent is an ester of an alcohol and a fatty acid.

[20-1] The resin composition according to item [20], wherein the esterof an alcohol and a fatty acid is monoglyceride stearate ormonoglyceride laurate.

[21] A polycarbonate resin composition, comprising:

a polycarbonate resin comprising a structural unit derived from acompound represented by general formula (1) below:

wherein X represents a C₁₋₁₀ alkylene group; and

a polycarbonate resin comprising a structural unit derived from acompound represented by general formula (2) below:

wherein R¹ and R² each independently represent a hydrogen atom, a C₁₋₂₀alkyl group, a C₁₋₂₀ alkoxyl group, a C₅₋₂₀ cycloalkyl group, a C₅₋₂₀cycloalkoxyl group, a C₆₋₂₀ aryl group or a C₆₋₂₀ aryloxy group and Rrepresents a hydrogen atom or a C₁₋₂₀ hydroxyalkyl group, thepolycarbonate resin composition having a phenol content of 0.1 to 3000ppm.[22] A polycarbonate resin composition, comprising:

a polycarbonate resin comprising a structural unit derived from acompound represented by general formula (1) below:

wherein X represents a C₁₋₁₀ alkylene group; and

a polycarbonate resin comprising a structural unit derived from acompound represented by general formula (2) below:

wherein R¹ and R² each independently represent a hydrogen atom, a C₁₋₂₀alkyl group, a C₁₋₂₀ alkoxyl group, a C₅₋₂₀ cycloalkyl group, a C₅₋₂₀cycloalkoxyl group, a C₆₋₂₀ aryl group or a C₆₋₂₀ aryloxy group and Rrepresents a hydrogen atom or a C₁₋₂₀ hydroxyalkyl group, thepolycarbonate resin composition having a carbonic acid diester contentof 0.1 to 1000 ppm.[23] The resin composition according to item [20] or [21], furthercomprising an antioxidant and/or a mold release agent.[24] The resin composition according to item [23], wherein theantioxidant is pentaerythritoltetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate].[25] The resin composition according to item [22] or [23], wherein themold release agent is an ester of an alcohol and a fatty acid.[25-1] The resin composition according to item [25], wherein the esterof an alcohol and a fatty acid is monoglyceride stearate ormonoglyceride laurate.<1> A resin produced by polycondensation of:

a compound having a binaphthyl skeleton represented by general formula(1):

wherein X represents a C₁₋₁₀ alkylene group; and

a compound having a fluorene skeleton represented by general formula(4):

wherein Y represents an organic group having 1 to 40 carbon atoms and 1to 4 oxygen atoms, which has at least one functional group selected froma hydroxyl group, a hydroxycarbonyl group, an alkoxycarbonyl group, anacyloxycarbonyl group and a halogenated carbonyl group,in the condition of

(a) with or without combined use of a compound having 2 or morefunctional groups which are at least one selected from a hydroxyl group,a hydroxycarbonyl group, an alkoxycarbonyl group, an acyloxycarbonylgroup and a halogenated carbonyl group, and

(b) with or without use of a carbonic acid diester.

<2> A resin composition obtained by mixing:

(a) a resin produced by polycondensation of a compound having abinaphthyl skeleton represented by general formula (1) in the conditionof

with or without combined use of a compound having 2 or more functionalgroups which are at least one type selected from a hydroxyl group, ahydroxycarbonyl group, an alkoxycarbonyl group, an acyloxycarbonyl groupand a halogenated carbonyl group, and

with or without use of a carbonic acid diester; and

(b) a resin produced by polycondensation of a compound having a fluoreneskeleton represented by general formula (4) in the condition of

with or without combined use of a compound having 2 or more functionalgroups which are at least one type selected from a hydroxyl group, ahydroxycarbonyl group, an alkoxycarbonyl group, an acyloxycarbonyl groupand a halogenated carbonyl group, and

with or without use of a carbonic acid diester.

<3> The resin according to item <1> or the resin composition accordingto item <2>, wherein the compound represented by general formula (4) isa compound represented by general formula (2a):

wherein R¹ and R² each independently represent a hydrogen atom, a C₁₋₂₀alkyl group, a C₁₋₂₀ alkoxyl group, a C₅₋₂₀ cycloalkyl group, a C₅₋₂₀cycloalkoxyl group, a C₆₋₂₀ aryl group or a C₆₋₂₀ aryloxy group.<4> The resin according to item <1> or the resin composition accordingto item <2>, wherein the compound represented by general formula (4) isa compound represented by general formula (2b):

wherein R¹ and R² each independently represent a hydrogen atom, a C₁₋₂₀alkyl group, a C₁₋₂₀ alkoxyl group, a C₅₋₂₀ cycloalkyl group, a C₅₋₂₀cycloalkoxyl group, a C₆₋₂₀ aryl group or a C₆₋₂₀ aryloxy group.<5> The resin according to item <1> or the resin composition accordingto item <2>, wherein the compound represented by general formula (4) isa compound represented by general formula (3):

wherein Ys each independently represent a single bond, a C₁₋₂₀ alkylgroup, a C₁₋₂₀ alkoxyl group, a C₅₋₂₀ cycloalkyl group, a C₅₋₂₀cycloalkoxyl group, a C₆₋₂₀ aryl group or a C₆₋₂₀ aryloxy group.

Advantageous Effects of the Invention

According to the present invention, it is possible to obtain a resinhaving excellent optical characteristics such as a high refractive indexand a low Abbe number.

DESCRIPTION OF EMBODIMENTS

The resin of the embodiment of the present invention is a resin producedby polycondensation using at least a compound represented by generalformula (1) and a compound represented by general formula (2) as rawmaterials.

The resin produced by polycondensation is preferably polyester,polyester carbonate or polycarbonate.

The structural unit derived from the compound represented by generalformula (1) contributes to a high refractive index, and in addition,contributes to reduction of the Abbe number more than the structuralunit derived from the compound represented by general formula (2). Thestructural unit derived from the compound represented by general formula(2) contributes to a high refractive index and a low Abbe number, and inaddition, has effects of reducing a birefringence value derived from thecompound represented by general formula (1) and reducing opticaldistortion of an optical molded body.

Optical characteristics such as the refractive index, Abbe number andbirefringence value are significantly affected by chemical structures ofstructural units, and the influence related to the matter as to whethera chemical bond between structural units is an ester bond or carbonatebond is relatively small.

In the compound represented by general formula (1), the functional groupwhich contributes to polycondensation is an alcoholic hydroxyl group.

In the compound represented by general formula (2), a typical example ofthe functional group which contributes to polycondensation is a hydroxylgroup, and examples thereof include an alcoholic hydroxyl group, aphenolic hydroxyl group and a carboxylic hydroxyl group.

The resin of the embodiment has a structural unit derived from adihydroxy compound (excluding dicarboxylic acid) and a structural unitderived from a dicarboxylic acid, but it does not mean that rawmaterials of the resin are limited to the dihydroxy compound and thedicarboxylic acid. For example, in addition to the dicarboxylic acid, anester, an acid anhydride and an acid halide of the dicarboxylic acid mayalso be used as raw materials.

In this specification, a component derived from the dihydroxy compoundin the resin is sometimes referred to as a “dihydroxy component” or“dihydroxy structural unit”, and a component derived from thedicarboxylic acid is sometimes referred to as a “dicarboxylic acidcomponent” or “dicarboxylic acid structural unit”. Further, in thisspecification, unless otherwise indicated, carboxylic acid is a type ofhydroxy compound and dicarboxylic acid is a type of dihydroxy compound.

In another embodiment, a resin composition obtained by mixing a resinobtained by polycondensation of at least the compound represented bygeneral formula (1) and a resin obtained by polycondensation of at leastthe compound represented by general formula (2) is also provided.Accordingly, the resin composition contains the structural unit derivedfrom the compound represented by general formula (1) and the structuralunit derived from the compound represented by general formula (2).

Optical characteristics such as the refractive index, Abbe number andbirefringence value are significantly affected by structures of thesestructural units, and the influence related to the matter as to whetherthe structural units exist in one molecule as in the case of copolymersor exist in a plurality of molecules as in the case of mixtures isrelatively small.

<Compound Represented by General Formula (1)>

(X represents a C₁₋₁₀ alkylene group.)

Examples of the dihydroxy compound represented by general formula (1)include 2,2′-bis(hydroxymethoxy)-1,1′-binaphthalene,2,2′-bis(2-hydroxyethoxy)-1,1′-binaphthalene,2,2′-bis(3-hydroxypropyloxy)-1,1′-binaphthalene and2,2′-bis(4-hydroxybutoxy)-1,1′-binaphthalene. Among them,2,2′-bis(2-hydroxyethoxy)-1,1′-binaphthalene is preferably used.

<Compound Represented by General Formula (2)>

[In formula (2), R¹ and R² each independently represent a hydrogen atom,a C₁₋₂₀ alkyl group, a C₁₋₂₀ alkoxyl group, a C₅₋₂₀ cycloalkyl group, aC₅₋₂₀ cycloalkoxyl group, a C₆₋₂₀ aryl group or a C₆₋₂₀ aryloxy groupand R represents a hydrogen atom or a C₁₋₂₀ hydroxyalkyl group.]

Among compounds represented by general formula (2), a compound having afluorene structure represented by general formula (2a) or (2b) ispreferably used. It is sufficient when at least one of such compounds isused, and two or more of them may be used in combination.

(In formula (2a), R¹ and R² each independently represent a hydrogenatom, a C₁₋₂₀ alkyl group, a C₁₋₂₀ alkoxyl group, a C₅₋₂₀ cycloalkylgroup, a C₅₋₂₀ cycloalkoxyl group, a C₆₋₂₀ aryl group or a C₆₋₂₀ aryloxygroup.)

As R¹ and R², preferred is a hydrogen atom, a C₁₋₁₂ alkyl group or aC₆₋₁₂ aryl group; more preferred is a hydrogen atom, a methyl group, anethyl group, a propyl group, an isopropyl group, a butyl group, anisobutyl group, a sec-butyl group, a tert-butyl group, a cycloheptylgroup, a cyclopropyl group or a phenyl group; and particularly preferredis a hydrogen atom, a methyl group or a phenyl group.

Examples of the dihydroxy compound represented by formula (2a) include9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene,9,9-bis(4-(2-hydroxyethoxy)-3-methylphenyl)fluorene,9,9-bis(4-(2-hydroxyethoxy)-3,5-dimethylphenyl)fluorene,9,9-bis(4-(2-hydroxyethoxy)-3-tert-butylphenyl)fluorene,9,9-bis(4-(2-hydroxyethoxy)-3-isopropylphenyl)fluorene,9,9-bis(4-(2-hydroxyethoxy)-3-cyclohexylphenyl)fluorene and9,9-bis(4-(2-hydroxyethoxy)-3-phenylphenyl)fluorene. Among them,9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene is preferably used.

(In formula (2b), R¹ and R² each independently represent a hydrogenatom, a C₁₋₂₀ alkyl group, a C₁₋₂₀ alkoxyl group, a C₅₋₂₀ cycloalkylgroup, a C₅₋₂₀ cycloalkoxyl group, a C₆₋₂₀ aryl group or a C₆₋₂₀ aryloxygroup.)

As R¹ and R², preferred is a hydrogen atom, a C₁₋₁₂ alkyl group or aC₆₋₁₂ aryl group; more preferred is a hydrogen atom, a methyl group, anethyl group, a propyl group, an isopropyl group, a butyl group, anisobutyl group, a sec-butyl group, a tert-butyl group, a cycloheptylgroup, a cyclopropyl group or a phenyl group; and particularly preferredis a hydrogen atom or a methyl group.

Examples of the dihydroxy compound represented by formula (2b) include9,9-bis(4-hydroxyphenyl)fluorene,9,9-bis(4-hydroxy-3-methylphenyl)fluorene,9,9-bis(4-hydroxy-3-ethylphenyl)fluorene,9,9-bis(4-hydroxy-3-n-propylphenyl)fluorene,9,9-bis(4-hydroxy-3-isopropylphenyl)fluorene,9,9-bis(4-hydroxy-3-n-butylphenyl)fluorene,9,9-bis(4-hydroxy-3-sec-butylphenyl)fluorene,9,9-bis(4-hydroxy-3-tert-butylphenyl)fluorene,9,9-bis(4-hydroxy-3-cyclohexylphenyl)fluorene,9,9-bis(4-hydroxy-2-phenylphenyl)fluorene,9,9-bis(4-hydroxy-3-phenylphenyl)fluorene and9,9-bis[4-hydroxy-3-(3-methylphenyl)phenyl]fluorene. Among them,9,9-bis(4-hydroxy-3-phenylphenyl)fluorene and9,9-bis(4-hydroxy-3-methylphenyl)fluorene are preferred. These compoundsmay be used solely, or two or more of them may be used in combination.

As described above, the resin of the present invention is preferablypolyester, polyester carbonate or polycarbonate. Hereinafter, thesepreferred resins will be respectively described in detail.

1. Polycarbonate Resin

The polycarbonate resin of the embodiment is a polycarbonate resinhaving: a structural unit derived from a compound represented by generalformula (1) (hereinafter sometimes referred to as “structural unit(A)”); and a structural unit derived from a compound represented bygeneral formula (2) (excluding carboxylic acid) (hereinafter sometimesreferred to as “structural unit (B)”). In the polycarbonate resin, thestructural units are bound to each other via a carbonate bond.

[In formula (1), X represents a C₁₋₁₀ alkylene group.]

[In formula (2):

R¹ and R² each independently represent a hydrogen atom, a C₁₋₂₀ alkylgroup, a C₁₋₂₀ alkoxyl group, a C₅₋₂₀ cycloalkyl group, a C₅₋₂₀cycloalkoxyl group, a C₆₋₂₀ aryl group or a C₆₋₂₀ aryloxy group; and

R represents a hydrogen atom or a C₁₋₂₀ hydroxyalkyl group.]

As the compound represented by general formula (2) (excluding carboxylicacid), a compound represented by general formula (2a) and a compoundrepresented by general formula (2b) can be suitably used.

(In formula (2a), R¹ and R² are as defined with respect to formula (2)above.)

(In formula (2b), R¹ and R² are as defined with respect to formula (2)above.)

Note that details of the compound represented by general formula (2a) or(2b) are as described above.

As dihydroxy components, in addition to the compound of general formula(1) and the compound of general formula (2) (excluding carboxylic acid),an aromatic dihydroxy compound and an aliphatic dihydroxy compound canbe used in combination.

Examples of the aromatic dihydroxy compound and the aliphatic dihydroxycompound include 4,4-bis(4-hydroxyphenyl)propane [=bisphenol A],1,1-bis(4-hydroxyphenyl)-1-phenylethane [=bisphenol AP],2,2-bis(4-hydroxyphenyl)hexafluoropropane [=bisphenol AF],2,2-bis(4-hydroxyphenyl)butane [=bisphenol B],bis(4-hydroxyphenyl)diphenylmethane [=bisphenol BP],bis(4-hydroxy-3-methylphenyl)propane [=bisphenol C],1,1-bis(4-hydroxyphenyl)ethane [=bisphenol E],bis(4-hydroxyphenyl)methane [=bisphenol F], bis(2-hydroxyphenyl)methane,2,2-bis(4-hydroxy-3-isopropylphenyl)propane [=bisphenol G],1,3-bis(2-(4-hydroxyphenyl)-2-propyl)benzene [=bisphenol M],bis(4-hydroxyphenyl)sulfone [=bisphenol S],1,4-bis(2-(4-hydroxyphenyl)-2-propyl)benzene [=bisphenol P],bis(4-hydroxy-3-phenylphenyl]propane [=bisphenol PH],1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane [=bisphenol TMC],1,1-bis(4-hydroxyphenyl)cyclohexane [=bisphenol Z],1,1-bis(4-hydroxy-3-methylphenyl)cyclohexane (bisphenol OCZ) and4,4-bisphenol.

(1) Polycarbonate resin comprising a structural unit derived from acompound represented by general formula (2a)

In a preferred embodiment, the polycarbonate resin comprises astructural unit (A) derived from a compound represented by generalformula (1) and a structural unit derived from a compound represented bygeneral formula (2a) (hereinafter sometimes referred to as “structuralunit (C)”).

The ratio of the total of the carbonate unit induced from the structuralunit (A) and the carbonate unit induced from the structural unit (C) ispreferably 50 mol % or more, more preferably 80 mol % or more,particularly preferably 90 mol % or more, and most preferably 100 mol %relative to all the carbonate units constituting the polycarbonateresin. The polycarbonate resin may contain a structural unit other thanthe structural units (A) and (C).

The molar ratio between the structural unit (A) and the structural unit(C) (A/C) is preferably 20/80 to 99/1, more preferably 30/70 to 95/5,and particularly preferably 40/60 to 90/10.

The ratio of the carbonate unit induced from the structural unit (A) ispreferably 1 to 99 mol % relative to all the carbonate unitsconstituting the polycarbonate resin.

The ratio of the carbonate unit induced from the structural unit (A) ismore preferably 30 to 90 mol %, and even more preferably 40 to 80 mol %relative to all the carbonate units constituting the polycarbonateresin.

The polystyrene equivalent weight-average molecular weight (Mw) of thepolycarbonate resin is preferably 20000 to 200000. The polystyreneequivalent weight-average molecular weight (Mw) is more preferably 25000to 120000, even more preferably 25000 to 60000, and particularlypreferably 40000 to 60000.

When Mw is less than 20000, a molded body becomes fragile and thereforeit is undesirable. When Mw is more than 200000, the melt viscosityincreases, resulting in difficulty in taking out a resin from a mold atthe time of molding, and in addition, the flowability is reduced,resulting in difficulty in injection molding in a molten state, andtherefore it is undesirable.

The polycarbonate resin may have a structure of either a randomcopolymer, block copolymer or alternating copolymer.

The refractive index (nD) of the polycarbonate resin at 23° C. at awavelength of 589 nm is preferably 1.640 to 1.680, more preferably 1.645to 1.675, and even more preferably 1.650 to 1.670. The above-describedpolycarbonate resin has a high refractive index (nD) and is suitable asan optical lens material. The refractive index can be measured by themethod of JIS-K-7142 using a film having a thickness of 0.1 mm and anAbbe's refractometer.

The Abbe number (v) of the polycarbonate resin is preferably 24 or less,more preferably 23 or less, and even more preferably 22 or less. TheAbbe number can be calculated from refractive indexes at wavelengths of486 nm, 589 nm and 656 nm at 23° C., using the below-described formula:v=(nD−1)/(nF−nC)

nD: refractive index at a wavelength of 589 nm

nC: refractive index at a wavelength of 656 nm

nF: refractive index at a wavelength of 486 nm

When using this resin for injection molding, the glass transitiontemperature (Tg) is preferably 95 to 180° C., more preferably 110 to170° C., even more preferably 115 to 160° C., and particularlypreferably 125 to 145° C. When Tg is lower than 95° C., the operatingtemperature range is narrowed, and therefore it is undesirable. When Tgis higher than 180° C., the melting temperature of the resin increases,decomposition and coloring of the resin tend to be easily caused, andtherefore it is undesirable. Further, when the glass transitiontemperature of the resin is too high, in the case of using a widely-usedmold temperature controller, the difference between the mold temperatureand the glass transition temperature of the resin increases. For thisreason, it is difficult to use a resin having a too high glasstransition temperature for applications which require exact surfaceaccuracy of products, and therefore it is undesirable.

As an index of thermal stability for resisting heating at the time ofinjection molding, the 5% weight reduction temperature (Td) of thepolycarbonate resin measured at a temperature raising rate of 10° C./minis preferably 350° C. or higher. When the 5% weight reductiontemperature is lower than 350° C., the resin is thermally decomposedsignificantly at the time of molding and it is difficult to obtain agood molded body, and therefore it is undesirable.

Regarding the polycarbonate resin, the orientation birefringence (Δn)that is a scale of the amount of birefringence is preferably 1.0×10⁻³ orless, more preferably 0.8×10⁻³ or less, even more preferably 0.3×10⁻³ orless, and particularly preferably 0.2×10⁻³ or less.

Regarding Δn, a cast film having a thickness of 0.1 mm is cut into a5.0×5.0 cm square; after that, both the ends of the film are sandwichedbetween chucks (distance between the chucks: 3.0 cm); the film isstretched 1.5-fold at a temperature of Tg of the polycarbonate resin+5°C.; the phase difference (Re) at 589 nm is measured using anellipsometer M-220 manufacture by JASCO Corporation; and after that, Δncan be obtained from the below-described formula:Δn=Re/d

Δn: orientation birefringence

Re: phase difference

d: thickness

Regarding signs of the birefringence (Δn), it is represented by thebelow-described formula using the refractive index in the filmstretching direction (n//) and the refractive index in the directionperpendicular to the stretching direction (n⊥), and the case where Δn ispositive is referred to as “positive birefringence” and the case whereΔn is negative is referred to as “negative birefringence”.Δn=n//−n⊥

In the polycarbonate resin, phenol produced at the time of theproduction and carbonic acid diester which is unreacted and remains arepresent as impurities. The phenol content in the polycarbonate resin ispreferably 0.1 to 3000 ppm, more preferably 0.1 to 2000 ppm, andparticularly preferably 1 to 1000 ppm, 1 to 800 ppm, 1 to 500 ppm or 1to 300 ppm. Further, the carbonic acid diester content in thepolycarbonate resin is preferably 0.1 to 1000 ppm, more preferably 0.1to 500 ppm, and particularly preferably 1 to 100 ppm. By adjusting theamounts of phenol and carbonic acid diester contained in thepolycarbonate resin, a resin having physical properties appropriate forpurposes can be obtained. The adjustment of the phenol content and thecarbonic acid diester content can be suitably carried out by changingconditions for polycondensation and apparatuses. The adjustment can alsobe carried out by changing conditions for the extrusion process afterpolycondensation.

When the content of phenol or carbonic acid diester is more than theabove-described ranges, it may cause problems such as reduction in thestrength of a resin molded body obtained and generation of odor.Meanwhile, when the content of phenol or carbonic acid diester is lessthan the above-described ranges, it may cause reduction in theplasticity of a resin at the time of melting.

The total light transmittance of an optical molded body obtained byusing the polycarbonate resin is preferably 85% or more, and morepreferably 88% or more, and is comparable to those of a bisphenol A-typepolycarbonate resin, etc.

Moreover, to the polycarbonate resin, an antioxidant, a mold releaseagent, an ultraviolet absorber, a flowability improving agent, a crystalnucleating agent, a toughening agent, a dye, an antistatic agent, anantimicrobial agent or the like may be added.

(2) Method for producing a polycarbonate resin comprising a structuralunit derived from a compound represented by general formula (2a)

The polycarbonate resin having a structural unit derived from a compoundrepresented by general formula (2a) can be produced by the meltpolycondensation method using a compound represented by general formula(1), a compound represented by general formula (2a) and a carbonateprecursor such as a carbonic acid diester in the presence or absence ofa basic compound catalyst or a transesterification catalyst or a mixedcatalyst made of both of them.

Examples of the carbonic acid diester to be used in the reaction includediphenyl carbonate, ditolyl carbonate, bis(chlorophenyl) carbonate,m-cresyl carbonate, dimethyl carbonate, diethyl carbonate, dibutylcarbonate and dicyclohexyl carbonate. Among them, diphenyl carbonate isparticularly preferred. The carbonic acid diester is used at a ratio ofpreferably 0.97 to 1.20 mol, and more preferably 0.98 to 1.10 molrelative to 1 mol of the total of the dihydroxy compounds. When theamount of the carbonic acid diester is not within these ranges, forexample, problems that a resin does not have a desired molecular weight,and that an unreacted raw material remains in a resin, resulting inreduction in optical characteristics may be caused.

Examples of the basic compound catalyst particularly include an alkalimetal compound, an alkaline earth metal compound and anitrogen-containing compound.

Examples of the alkali metal compound include an organic salt, inorganicsalt, oxide, hydroxide, hydride or alkoxide of an alkali metal, etc.Specific examples thereof include sodium hydroxide, potassium hydroxide,cesium hydroxide, lithium hydroxide, sodium hydrogen carbonate, sodiumcarbonate, potassium carbonate, cesium carbonate, lithium carbonate,sodium acetate, potassium acetate, cesium acetate, lithium acetate,sodium stearate, potassium stearate, cesium stearate, lithium stearate,sodium borohydride, sodium tetraphenylborate, sodium benzoate, potassiumbenzoate, cesium benzoate, lithium benzoate, disodium hydrogenphosphate, dipotassium hydrogen phosphate, dilithium hydrogen phosphate,disodium phenyl phosphate, a disodium salt, dipotassium salt, dicesiumsalt or dilithium salt of bisphenol A, and a sodium salt, potassiumsalt, cesium salt or lithium salt of phenol. Among them, sodium hydrogencarbonate is preferred because an inexpensive high-purity sodiumhydrogen carbonate having high catalytic activity is distributed.

Examples of the alkaline earth metal compound include an organic salt,inorganic salt, oxide, hydroxide, hydride or alkoxide of an alkalineearth metal, etc. Specific examples thereof include magnesium hydroxide,calcium hydroxide, strontium hydroxide, barium hydroxide, magnesiumhydrogen carbonate, calcium hydrogen carbonate, strontium hydrogencarbonate, barium hydrogen carbonate, magnesium carbonate, calciumcarbonate, strontium carbonate, barium carbonate, magnesium acetate,calcium acetate, strontium acetate, barium acetate, magnesium stearate,calcium stearate, calcium benzoate and magnesium phenyl phosphate.

Examples of the nitrogen-containing compound include quaternary ammoniumhydroxides and salts thereof, and amines. Specific examples thereofinclude: quaternary ammonium hydroxides having an alkyl group, arylgroup or the like such as tetramethylammonium hydroxide,tetraethylammonium hydroxide, tetrapropylammonium hydroxide,tetrabutylammonium hydroxide and trimethylbenzylammonium hydroxide;tertiary amines such as triethylamine, dimethylbenzylamine andtriphenylamine; secondary amines such as diethylamine and dibutylamine;primary amines such as propylamine and butylamine; imidazoles such as2-methylimidazole, 2-phenylimidazole and benzimidazole; and bases orbasic salts such as ammonia, tetramethylammonium borohydride,tetrabutylammonium borohydride, tetrabutylammonium tetraphenylborate andtetraphenylammonium tetraphenylborate.

As the transesterification catalyst, salts of zinc, tin, zirconium,lead, etc. are preferably used. These substances may be used solely, ortwo or more of them may be used in combination.

As the transesterification catalyst, zinc acetate, zinc benzoate, zinc2-ethylhexanoate, tin(II) chloride, tin(IV) chloride, tin(II) acetate,tin(IV) acetate, dibutyltin dilaurate, dibutyltin oxide, dibutyltindimethoxide, zirconium acetylacetonato, zirconium oxyacetate, zirconiumtetrabutoxide, lead(II) acetate, lead(IV) acetate or the like isspecifically used.

These catalysts are used at a ratio of 1×10⁻⁹ to 1×10⁻³ mol, andpreferably 1×10⁻⁷ to 1×10⁻⁴ mol relative to 1 mol of the total of thedihydroxy compounds.

Regarding the catalyst, two or more types of such catalysts may be usedin combination. Further, the catalyst itself may be added directly, ormay be dissolved in a solvent such as water and phenol and then added.

In the melt polycondensation method, using the aforementioned rawmaterials and catalyst, melt polycondensation is carried out whileremoving a by-product by means of the transesterification reaction underheating conditions and under ordinary pressure or reduced pressure. Thecatalyst may be present from the start of the reaction together with theraw materials, or may be added in the middle of the reaction.

In the case of melt polycondensation in this composition system, afterthe compounds represented by general formula (1) and general formula(2a) and the carbonic acid diester are melted in a reactor, the reactionmay be performed with a monohydroxy compound by-produced being retained,but not distilled away. When the reaction is performed with themonohydroxy compound by-produced being retained, but not distilled away,the reaction time is 20 minutes to 240 minutes, preferably 40 minutes to180 minutes, and particularly preferably 60 minutes to 150 minutes. Inthis regard, when the monohydroxy compound by-produced is distilled awayimmediately after it is produced, the content of a high-molecular-weightbody in the polycarbonate resin finally obtained is decreased. Preferredreaction time may vary depending on a reaction scale.

The melt polycondensation reaction may be either a continuous type or abatch type. The reaction apparatus to be used for performing thereaction may be a vertical apparatus equipped with an anchor typestirring blade, max blend stirring blade, helicalribbon type stirringblade or the like, or a horizontal apparatus equipped with a paddleblade, lattice blade, spectacle-shaped blade or the like, or anextruder-type apparatus equipped with a screw. Further, use of thesereaction apparatuses in combination is suitably carried out inconsideration of the viscosity of a polymerized product.

In the method for producing the polycarbonate resin, after thepolymerization reaction is completed, in order to maintain thermalstability and hydrolytic stability, the catalyst may be removed ordeactivated, but is not necessarily required to be deactivated. When thecatalyst is deactivated, a method for deactivating a catalyst by meansof addition of a publicly-known acidic substance can be suitably carriedout. As the acidic substance, specifically, esters such as butylbenzoate; aromatic sulfonic acids such as p-toluenesulfonic acid;aromatic sulfonic acid esters such as butyl p-toluenesulfonate and hexylp-toluenesulfonate; phosphoric acids such as phosphorous acid,phosphoric acid and phosphonic acid; phosphorous acid esters such astriphenyl phosphite, monophenyl phosphite, diphenyl phosphite, diethylphosphite, di-n-propyl phosphite, di-n-butyl phosphite, di-n-hexylphosphite, dioctyl phosphite and monooctyl phosphite; phosphoric acidesters such as triphenyl phosphate, diphenyl phosphate, monophenylphosphate, dibutyl phosphate, dioctyl phosphate and monooctyl phosphate;phosphonic acids such as diphenylphosphonic acid, dioctylphosphonic acidand dibutylphosphonic acid; phosphonic acid esters such as diethylphenylphosphonate; phosphines such as triphenyl phosphine andbis(diphenylphosphino)ethane; boric acids such as boric acid andphenylboric acid; aromatic sulfonates such as dodecylbenzenesulfonicacid tetrabutylphosphonium salt; organic halides such as stearic acidchloride, benzoyl chloride and p-toluenesulfonic acid chloride; alkylsulfates such as dimethyl sulfate; organic halides such as benzylchloride; etc. are preferably used. From the viewpoint of effects of adeactivating agent, stability against the resin, etc., p-toluene orbutyl sulfonate is particularly preferred. These deactivating agents areused in an amount of 0.01 to 50 times, and preferably 0.3 to 20 timesthe molar quantity of the catalyst. When the amount is less than 0.01times the molar quantity of the catalyst, the deactivating effect isinsufficient and therefore it is undesirable. When the amount is morethan 50 times the molar quantity of the catalyst, heat resistance of theresin is reduced and a molded body tends to be easily colored, andtherefore it is undesirable.

The addition of the deactivating agent can be carried out by means ofkneading, and either a continuous type or a batch type may be employed.The temperature at the time of kneading is preferably 200 to 350° C.,more preferably 230 to 300° C., and particularly preferably 250 to 270°C. As the kneading machine, an extruder is suitably used in the case ofthe continuous type method, and Labo Plastomill or a kneader is suitablyused in the case of the batch type method. Examples of the extruderinclude a single screw extruder, a twin screw extruder, a multi-screwextruder, etc. To the extruder, for example, a gear pump for performingstable quantification of the resin discharge amount can be suitablyprovided. The atmosphere pressure for melting and kneading the resincomposition is not particularly limited, and ordinary pressure orreduced pressure, for example, a pressure ranging from ordinary pressure(760 mmHg) to 0.1 mmHg is preferred in terms of antioxidation andremoval of decomposed materials and low boiling point components such asphenol. The extruder may be either a vent-type extruder or anon-vent-type extruder, but from the viewpoint of quality improvement ofextruded products, preferred is a vent-type extruder. The pressure at avent port (vent pressure) may be either ordinary pressure or reducedpressure, but for example, it may be a pressure ranging from ordinarypressure (760 mmHg) to 0.1 mmHg, and it is preferably a pressure ofabout 100 to 0.1 mmHg, and more preferably a pressure of about 50 to 0.1mmHg in terms of antioxidation and removal of decomposed materials andlow boiling point components such as phenol. Further, hydrogenation anddevolatilization may also be carried out for the purpose of moreefficiently reducing low boiling point components such as phenol.

Kneading of the deactivating agent may be carried out immediately afterthe polymerization reaction is completed, or may be carried out afterthe resin after the polymerization is pelletized. Further, in additionto the deactivating agent, other additives (antioxidant, mold releaseagent, ultraviolet absorber, flowability improving agent, crystalnucleating agent, toughening agent, dye, antistatic agent, antimicrobialagent, etc.) may also be added in a similar manner.

After the catalyst is deactivated (in the case where the deactivatingagent is not added, after the polymerization reaction is completed), aprocess of devolatilizing and removing a low boiling point compound inthe polymer under a pressure of 0.1 to 1 mmHg and at a temperature of200 to 350° C. may be carried out. The temperature at the time ofdevolatilizing and removing is preferably 230 to 300° C., and morepreferably 250 to 270° C. In this process, a horizontal apparatusequipped with a stirring blade having excellent surface renewal abilitysuch as a paddle blade, a lattice blade and a spectacle-shaped blade, ora thin film evaporator is suitably used.

It is desired that the content of foreign materials in the polycarbonateresin is as small as possible, and filtration of a melting raw material,filtration of a catalyst solution, etc. are suitably carried out. Themesh of the filter is preferably 5 μm or less, and more preferably 1 μmor less. Moreover, filtration of the produced resin using a polymerfilter is suitably carried out. The mesh of the polymer filter ispreferably 100 μm or less, and more preferably 30 μm or less. Further,the process of obtaining a resin pellet should definitely be carried outin a low-dust environment, which is preferably Class 6 or lower, andmore preferably Class 5 or lower.

(3) Optical Molded Body Obtained by Using Polycarbonate Resin

An optical molded body can be produced using the above-describedpolycarbonate resin. It is molded according to any method, for example,the injection molding method, compression molding method, extrusionmolding method, solution casting method or the like. The polycarbonateresin of the embodiment is excellent in moldability and heat resistance,and therefore can be advantageously used particularly for optical lenseswhich require injection molding. At the time of molding, thepolycarbonate resin of the embodiment can be mixed with another resinsuch as another polycarbonate resin and a polyester resin to be used. Inaddition, additives such as an antioxidant, a processing stabilizer, alight stabilizer, a heavy metal deactivator, a flame retardant, alubricant, an antistatic agent, a surfactant, an antimicrobial agent, amold release agent, an ultraviolet absorber, a plasticizer and acompatibilizer may be mixed therewith.

Examples of the antioxidant include triethyleneglycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate],1,6-hexanediol-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate],pentaerythritoltetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate],octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate,1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene,N,N-hexamethylene bis(3,5-di-tert-butyl-4-hydroxy-hydrocinnamide),3,5-di-tert-butyl-4-hydroxy-benzylphosphonate-diethyl ester,tris(3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate and3,9-bis{1,1-dimethyl-2-[β-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl}-2,4,8,10-tetraoxaspiro(5,5)undecane.The content of the antioxidant in the polycarbonate resin is preferably0.001 to 0.3 parts by weight relative to 100 parts by weight of thepolycarbonate resin.

Examples of the processing stabilizer include a phosphorus-basedprocessing heat stabilizer and a sulfur-based processing heatstabilizer. Examples of the phosphorus-based processing heat stabilizerinclude phosphorous acid, phosphoric acid, phosphonous acid, phosphonicacid and esters thereof. Specific examples thereof include triphenylphosphite, tris(nonylphenyl) phosphite, tris(2,4-di-tert-butylphenyl)phosphite, tris(2,6-di-tert-butylphenyl) phosphite, tridecyl phosphite,trioctyl phosphite, trioctadecyl phosphite, didecylmonophenyl phosphite,dioctylmonophenyl phosphite, diisopropylmonophenyl phosphite,monobutyldiphenyl phosphite, monodecyldiphenyl phosphite,monooctyldiphenyl phosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, 2,2-methylenebis(4,6-di-tert-butylphenyl)octylphosphite, bis(nonylphenyl) pentaerythritol diphosphite,bis(2,4-dicumylphenyl) pentaerythritol diphosphite,bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite,distearylpentaerythritol diphosphite, tributyl phosphate, triethylphosphate, trimethyl phosphate, triphenyl phosphate, diphenylmonoorthoxenyl phosphate, dibutyl phosphate, dioctyl phosphate,diisopropyl phosphate, dimethyl benzenephosphonate, diethylbenzenephosphonate, dipropyl benzenephosphonate,tetrakis(2,4-di-t-butylphenyl)-4,4′-biphenylene diphosphonate,tetrakis(2,4-di-t-butylphenyl)-4,3′-biphenylene diphosphonate,tetrakis(2,4-di-t-butylphenyl)-3,3′-biphenylene diphosphonate,bis(2,4-di-tert-butylphenyl)-4-phenyl-phenylphosphonate andbis(2,4-di-tert-butylphenyl)-3-phenyl-phenylphosphonate. The content ofthe phosphorus-based processing heat stabilizer in the polycarbonateresin is preferably 0.001 to 0.2 parts by weight relative to 100 partsby weight of the polycarbonate resin.

Examples of the sulfur-based processing heat stabilizer includepentaerythritol-tetrakis(3-lauryl thiopropionate),pentaerythritol-tetrakis(3-myristyl thiopropionate),pentaerythritol-tetrakis(3-stearyl thiopropionate),dilauryl-3,3′-thiodipropionate, dimyristyl-3,3′-thiodipropionate anddistearyl-3,3′-thiodipropionate. The content of the sulfur-basedprocessing heat stabilizer in the polycarbonate resin is preferably0.001 to 0.2 parts by weight relative to 100 parts by weight of thepolycarbonate resin.

Regarding the mold release agent, it is preferred that 90 wt % or moreof it is made of an ester of an alcohol and a fatty acid. Specificexamples of the ester of an alcohol and a fatty acid include an ester ofa monohydric alcohol and a fatty acid and a partial ester or whole esterof a polyhydric alcohol and a fatty acid. As the above-described esterof a monohydric alcohol and a fatty acid, an ester of a monohydricalcohol having 1 to 20 carbon atoms and a saturated fatty acid having 10to 30 carbon atoms is preferred. Further, as the partial ester or wholeester of a polyhydric alcohol and a fatty acid, a partial ester or wholeester of a polyhydric alcohol having 1 to 25 carbon atoms and asaturated fatty acid having 10 to 30 carbon atoms is preferred.

Specific examples of the ester of a monohydric alcohol and a saturatedfatty acid include stearyl stearate, palmityl palmitate, butyl stearate,methyl laurate and isopropyl palmitate. Specific examples of the partialester or whole ester of a polyhydric alcohol and a saturated fatty acidinclude whole esters or partial esters of monoglyceride stearate,diglyceride stearate, triglyceride stearate, monosorbitate stearate,monoglyceride behenate, monoglyceride caprate, monoglyceride laurate,pentaerythritol monostearate, pentaerythritol tetrastearate,pentaerythritol tetrapelargonate, propylene glycol monostearate,biphenyl biphenate, sorbitan monostearate, 2-ethylhexyl stearate anddipentaerythritols such as dipentaerythritol hexastearate. Among them,monoglyceride stearate and monoglyceride laurate are particularlypreferred. The content of these mold release agents is preferably 0.005to 2.0 parts by weight, more preferably 0.01 to 0.6 parts by weight, andeven more preferably 0.02 to 0.5 parts by weight relative to 100 partsby weight of the polycarbonate resin.

The ultraviolet absorber is preferably at least one ultraviolet absorberselected from the group consisting of a benzotriazole-based ultravioletabsorber, a benzophenone-based ultraviolet absorber, a triazine-basedultraviolet absorber, a cyclic iminoester-based ultraviolet absorber anda cyanoacrylate-based ultraviolet absorber. That is, ultravioletabsorbers mentioned below may be used solely, or two or more of them maybe used in combination.

Examples of the benzotriazole-based ultraviolet absorber include2-(2-hydroxy-5-methylphenyl)benzotriazole,2-(2-hydroxy-5-tert-octylphenyl)benzotriazole,2-(2-hydroxy-3,5-dicumylphenyl)phenylbenzotriazole,2-(2-hydroxy-3-tert-butyl-5-methylphenyl)-5-chlorobenzotriazole,2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2N-benzotriazol-2-yl)phenol],2-(2-hydroxy-3,5-di-tert-butylphenyl)benzotriazole,2-(2-hydroxy-3,5-di-tert-butylphenyl)-5-chlorobenzotriazole,2-(2-hydroxy-3,5-di-tert-amylphenyl)benzotriazole,2-(2-hydroxy-5-tert-octylphenyl)benzotriazole,2-(2-hydroxy-5-tert-butylphenyl)benzotriazole,2-(2-hydroxy-4-octoxyphenyl)benzotriazole,2,2′-methylenebis(4-cumyl-6-benzotriazolephenyl),2,2′-p-phenylenebis(1,3-benzoxazin-4-one) and2-[2-hydroxy-3-(3,4,5,6-tetrahydrophthalimidomethyl)-5-methylphenyl]benzotriazole.

Examples of the benzophenone-based ultraviolet absorber include2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone,2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-benzyloxybenzophenone,2-hydroxy-4-methoxy-5-sulfoxybenzophenone,2-hydroxy-4-methoxy-5-sulfoxytrihydrate benzophenone,2,2′-dihydroxy-4-methoxybenzophenone,2,2′,4,4′-tetrahydroxybenzophenone,2,2′-dihydroxy-4,4′-dimethoxybenzophenone,2,2′-dihydroxy-4,4′-dimethoxy-5-sodiumsulfoxybenzophenone,bis(5-benzoyl-4-hydroxy-2-methoxyphenyl)methane,2-hydroxy-4-n-dodecyloxybenzophonone and2-hydroxy-4-methoxy-2′-carboxybenzophenone.

Examples of the triazine-based ultraviolet absorber include2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-[(hexyl)oxy]-phenol,2-(4,6-bis(2,4-dimethylphenyl)-1,3,5-triazin-2-yl)-5-[(octyl)oxy]-phenoland 2,4,6-tris(2-hydroxy-4-hexyloxy-3-methylphenyl)-1,3,5-triazine.

Examples of the cyclic iminoester-based ultraviolet absorber include2,2′-bis(3,1-benzoxazin-4-one),2,2′-p-phenylenebis(3,1-benzoxazin-4-one),2,2′-m-phenylenebis(3,1-benzoxazin-4-one),2,2′-(4,4′-diphenylene)bis(3,1-benzoxazin-4-one),2,2′-(2,6-naphthalene)bis(3,1-benzoxazin-4-one),2,2′-(1,5-naphthalene)bis(3,1-benzoxazin-4-one),2,2′-(2-methyl-p-phenylene)bis(3,1-benzoxazin-4-one),2,2′-(2-nitro-p-phenylene)bis(3,1-benzoxazin-4-one) and2,2′-(2-chloro-p-phenylene)bis(3,1-benzoxazin-4-one).

Examples of the cyanoacrylate-based ultraviolet absorber include1,3-bis-[(2′-cyano-3′,3′-diphenylacryloyl)oxy]-2,2-bis[(2-cyano-3,3-diphenylacryloyl)oxy]methyl)propane and1,3-bis-[(2-cyano-3,3-diphenylacryloyl)oxy]benzene.

The content of the ultraviolet absorber is preferably 0.01 to 3.0 partsby weight, more preferably 0.02 to 1.0 parts by weight, and even morepreferably 0.05 to 0.8 parts by weight relative to 100 parts by weightof the polycarbonate resin. When the content is within these ranges,sufficient weatherability can be imparted to the polycarbonate resinaccording to intended use.

The polycarbonate resin of the embodiment exhibits a high refractiveindex and excellent heat resistance, and further has flowabilityappropriate for molding. Moreover, the polycarbonate resin exhibits lowbirefringence and optical distortion is not easily caused thereby, andtherefore, other than as optical lenses, the polycarbonate resin can beadvantageously used as a structural material of optical components suchas a transparent conductive substrate to be used for a liquid crystaldisplay, an organic EL display, a solar cell, etc., an optical disk, aliquid crystal panel, an optical card, a sheet, a film, an opticalfiber, a connector, a vapor-deposited plastic reflection mirror and adisplay, or as an optical molded body appropriate for use as afunctional material.

To the surface of the optical molded body, a coat layer such as anantireflection layer, a hard coat layer or the like may be providedaccording to need. The antireflection layer may be either a single layeror a multilayer, and may be made of either an organic substance or aninorganic substance, but is preferably made of an inorganic substance.Specific examples thereof include oxides and fluorides such as siliconoxide, aluminium oxide, zirconium oxide, titanium oxide, cerium oxide,magnesium oxide and magnesium fluoride.

(Optical Lens)

An optical lens produced by using the polycarbonate resin of theembodiment has a high refractive index and excellent heat resistance,and therefore can be used in the field in which expensive glass lenseshaving a high refractive index have been conventionally used includingtelescopes, binoculars and television projectors and is very useful. Theoptical lens is preferably used in the form of an aspherical lensaccording to need. In the case of the aspherical lens, since thespherical aberration can be adjusted to be substantially zero by onelens, it is not necessary to remove the spherical aberration bycombining a plurality of spherical lenses, and reduction in weight andreduction in the production cost can be carried out. Accordingly, theaspherical lens is particularly useful as a camera lens among opticallenses.

The optical lens is molded by any method such as the injection moldingmethod, the compression molding method and the injection compressionmolding method. By using the polycarbonate resin of the embodiment, anaspherical lens having a high refractive index and low birefringence,which is technically difficult to obtain by processing a glass lens, canbe more conveniently obtained.

In order to avoid mixing of a foreign material in the optical lens asmuch as possible, the molding environment must be a low-dustenvironment, and it is preferably Class 6 or lower, and more preferablyClass 5 or lower.

(Optical Film)

An optical film produced by using the polycarbonate resin of theembodiment has excellent transparency and heat resistance, and thereforeis suitably used for a film for liquid crystal substrates, an opticalmemory card, etc.

In order to avoid mixing of a foreign material in the optical film asmuch as possible, the molding environment must be a low-dustenvironment, and it is preferably Class 6 or lower, and more preferablyClass 5 or lower.

(4) Polycarbonate Resin Composition

The above-described polycarbonate resin may be in the form of a resincomposition containing a plurality of resins. Specifically, thepolycarbonate resin composition comprises: a polycarbonate resin (E)having a structural unit (A) derived from a compound represented bygeneral formula (1); and a polycarbonate resin (F) having a structuralunit (B) derived from a compound represented by general formula (2)(excluding dicarboxylic acid).

As described above, the polycarbonate resin composition comprises atleast a polycarbonate resin (E) having a structural unit (A) derivedfrom a compound represented by general formula (1) and a polycarbonateresin (F) having a structural unit (B) derived from a compoundrepresented by general formula (2). The polycarbonate resin compositioncomprises a structural unit derived from preferably a compoundrepresented by general formula (2a) or (2b), and more preferably acompound represented by general formula (2a), which are included in thecompound represented by general formula (2).

The polycarbonate resin composition may contain another resin inaddition to the polycarbonate resin (E) and the polycarbonate resin (F)within a range in which the features of the present invention are notimpaired.

Examples of the above-described another resin which may be contained inthe polycarbonate resin composition include: polyethylene,polypropylene, polyvinyl chloride, polystyrene, (meth)acrylic resin, ABSresin, polyamide, polyacetal, polycarbonate (other than thepolycarbonate resin (E) and the polycarbonate resin (F)), polyphenyleneether, polyester, polyphenylene sulfide, polyimide, polyether sulfone,polyether ether ketone, fluororesin, cycloolefin polymer, ethylene-vinylacetate copolymer, epoxy resin, silicone resin, phenol resin,unsaturated polyester resin and polyurethane.

The content of the above-described another resin which may be containedin the polycarbonate resin composition is preferably 20 parts by mass orless, and more preferably 10 parts by mass or less relative to the totalmass of the polycarbonate resin (E) and the polycarbonate resin (F).

When the content of the above-described another resin is too much,compatibility is reduced, and transparency of the resin composition maybe reduced.

In order to keep optical distortion at a low level, the polycarbonateresin (E) is preferably composed of the carbonate unit induced from thestructural unit (A), and the polycarbonate resin (F) is preferablycomposed of the carbonate unit induced from the structural unit (B).Further, a resin composition composed of only the polycarbonate resin(E) and the polycarbonate resin (F) is particularly preferred.

In the polycarbonate resin composition, phenol produced at the time ofthe production of respective resins constituting the composition andcarbonic acid diester which is unreacted and remains are present asimpurities. The phenol content in the polycarbonate resin composition ispreferably 0.1 to 3000 ppm, more preferably 0.1 to 2000 ppm, andparticularly preferably 1 to 1000 ppm, 1 to 800 ppm, 1 to 500 ppm or 1to 300 ppm. Further, the carbonic acid diester content in thepolycarbonate resin composition is preferably 0.1 to 1000 ppm, morepreferably 0.1 to 500 ppm, and particularly preferably 1 to 100 ppm. Byadjusting the amounts of phenol and carbonic acid diester contained inthe polycarbonate resin composition, a resin composition having physicalproperties appropriate for purposes can be obtained. The adjustment ofthe phenol content and the carbonic acid diester content can be suitablycarried out by changing conditions for polycondensation and apparatuses.The adjustment can also be carried out by changing conditions for theextrusion process after polycondensation.

When the content of phenol or carbonic acid diester is more than theabove-described ranges, it may cause problems such as reduction in thestrength of a resin molded body obtained and generation of odor.Meanwhile, when the content of phenol or carbonic acid diester is lessthan the above-described ranges, it may cause reduction in theplasticity of a resin at the time of melting.

Hereinafter, the respective resins constituting the polycarbonate resincomposition will be described.

<Polycarbonate Resin (E)>

The polycarbonate resin (E) comprises the structural unit derived fromthe compound represented by general formula (1).

As a repeating structural unit of the polycarbonate resin (E), astructural unit derived from a compound other than the compoundrepresented by general formula (1) may be contained, but the amountthereof is desirably 20 mol % or less, and more desirably 10 mol % orless relative to 100 mol % of the structural unit (A). When the amountis within the above-described ranges, a high refractive index can beretained.

The polystyrene equivalent average molecular weight (Mw) of thepolycarbonate resin (E) is preferably 20000 to 200000, more preferably25000 to 120000, and particularly preferably 25000 to 50000.

When Mw is less than 20000, a resin becomes fragile and therefore it isundesirable. When Mw is more than 200000, the melt viscosity increases,resulting in difficulty in taking out a resin from a mold at the time ofmolding, and in addition, the flowability is reduced, resulting indifficulty in handling in a molten state, and therefore it isundesirable.

<Method for Producing the Polycarbonate Resin (E)>

The method for producing the polycarbonate resin (E) will be described.

The method for producing the polycarbonate resin (E) is not particularlylimited. For example, it can be produced by the melt polycondensationmethod using a dihydroxy compound represented by general formula (1) inthe presence of a carbonic acid diester and a catalyst. As the catalyst,a basic compound catalyst or a transesterification catalyst or a mixedcatalyst made of both of them can be used.

The polycarbonate resin (E) may contain a structural unit derived fromanother dihydroxy compound other than the dihydroxy compound representedby general formula (1). Examples of the above-described anotherdihydroxy compound include: an aliphatic dihydroxy compound such asethylene glycol, 1,3-propanediol, 1,2-propanediol, 1,4-butanediol,1,3-butanediol, 1,2-butanediol, 1,5-heptanediol and 1,6-hexanediol; analicyclic dihydroxy compound such as 1,2-cyclohexanedimethanol,1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol,tricyclodecanedimethanol, pentacyclopentadecanedimethanol,2,6-decalindimethanol, 1,5-decalindimethanol, 2,3-decalindimethanol,2,3-norbornanedimethanol, 2,5-norbornanedimethanol and1,3-adamantanedimethanol; and an aromatic bisphenol such as2,2-bis(4-hydroxyphenyl)propane [=bisphenol A],2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane,2,2-bis(4-hydroxy-3,5-diethylphenyl)propane,2,2-bis(4-hydroxy-(3,5-diphenyl)phenyl)propane,2,2-bis(4-hydroxy-3,5-dibromophenyl)propane,2,2-bis(4-hydroxyphenyl)pentane, 2,4′-dihydroxy-diphenylmethane,bis(4-hydroxyphenyl)methane, bis(4-hydroxy-5-nitrophenyl)methane,1,1-bis(4-hydroxyphenyl)ethane, 3,3-bis(4-hydroxyphenyl)pentane,1,1-bis(4-hydroxyphenyl)cyclohexane, bis(4-hydroxyphenyl)sulfone,2,4′-dihydroxydiphenylsulfone, bis(4-hydroxyphenyl)sulfide,4,4′-dihydroxydiphenylether, 4,4′-dihydroxy-3,3′-dichlorodiphenylether,9,9-bis(4-hydroxyphenyl)fluorene and9,9-bis(4-hydroxy-2-methylphenyl)fluorene.

In this regard, the above-described another dihydroxy compound is addedin an amount of desirably 20 mol % or less, and more desirably 10 mol %or less relative to 100 mol % of the structural unit derived from thedihydroxy compound represented by general formula (1). When the amountis within the above-described ranges, a high refractive index can beretained.

Specific production methods, compounds to be used, etc., are the same asthose described in “(2) Method for producing a polycarbonate resincomprising a structural unit derived from a compound represented bygeneral formula (2a)” above, except that the compound represented bygeneral formula (2a) is not used.

<Method for Producing the Polycarbonate Resin (F)>

The method for producing the polycarbonate resin (F) is the same as theabove-described method for producing the polycarbonate resin (E), exceptthat the compound represented by general formula (1) is changed to thecompound represented by general formula (2).

(5) Method for Producing the Polycarbonate Resin Composition

The method for producing the polycarbonate resin composition is notparticularly limited. For example, it can be produced by any of thefollowing methods:

[1] a method in which the polycarbonate resin (E) in a solid state ismixed with the polycarbonate resin (F) in a solid state and the mixtureis kneaded by a kneading machine;

[2] a method in which the polycarbonate resin (F) in a solid state isadded to the polycarbonate resin (E) in a molten state and the mixtureis kneaded;

[3] a method in which the polycarbonate resin (E) in a solid state isadded to the polycarbonate resin (F) in a molten state and the mixtureis kneaded; and

[4] a method in which the polycarbonate resin (E) in a molten state ismixed with the polycarbonate resin (F) in a molten state and the mixtureis kneaded.

Regarding kneading, either a continuous type method or a batch typemethod may be employed. As the kneading machine, an extruder is suitablyused in the case of the continuous type method, and Labo Plastomill or akneader is suitably used in the case of the batch type method.

The polycarbonate resin (E) and the polycarbonate resin (F) are blendedtogether with a weight ratio ((100×(E))/((E)+(F))) of preferably 1 to99%, more preferably 10 to 90%, even more preferably 25 to 60%, andparticularly preferably 40 to 70%.

Note that the polycarbonate resin composition may contain two or moretypes of each of the polycarbonate resin (E) and the polycarbonate resin(F). In this case, (E) and (F) in the formula (100×(E))/((E)+(F))respectively mean the total weight of the two or more types of thepolycarbonate resin (E) and the total weight of the two or more types ofthe polycarbonate resin (F).

The difference of the polystyrene equivalent weight-average molecularweight (ΔMw) between the polycarbonate resin (E) and the polycarbonateresin (F) is preferably 0 to 120,000, more preferably 0 to 80,000, andparticularly preferably 0 to 20,000. When the difference is within theabove-described ranges, the viscosity difference between thepolycarbonate resin (E) and the polycarbonate resin (F) is not toolarge, good compatibility is provided and a blended resin compositionhas high transparency, and therefore it is preferred.

Moreover, to the polycarbonate resin composition, an antioxidant, a moldrelease agent, an ultraviolet absorber, a flowability improving agent, atoughening agent, a crystal nucleating agent, a dye, an antistaticagent, an antimicrobial agent or the like may be added according toneed. These additives may be added in advance to each or either of thepolycarbonate resin (E) and the polycarbonate resin (F) beforeperforming kneading, and may be added and kneaded simultaneously at thetime of kneading or may be kneaded after mixing.

Further, the polycarbonate resin composition may contain a polycarbonateresin other than the polycarbonate resin (E) and the polycarbonate resin(F), but more preferably, does not substantially contain such apolycarbonate resin.

As the antioxidant, processing stabilizer, mold release agent andultraviolet absorber contained in the resin composition, the same thingsas those described in “(3) Optical molded body obtained by usingpolycarbonate resin” above can be used, and the same adding amounts canalso be employed.

(6) Optical Molded Body Obtained by Using Polycarbonate ResinComposition

Using the above-described polycarbonate resin composition, an opticalmolded body such as an optical lens and an optical film can be producedaccording to methods similar to those described in “(3) Optical moldedbody obtained by using polycarbonate resin” above. The polycarbonateresin composition of the embodiment is excellent in moldability and heatresistance, and therefore can be advantageously used particularly foroptical lenses which require injection molding.

Preferred physical properties of the polycarbonate resin composition andthe molded body are as described below.

The molecular weight (polystyrene equivalent weight-average molecularweight (Mw)) of the polycarbonate resin composition of the embodiment(after mixing) is preferably 20000 to 200000, more preferably 25000 to120000, and particularly preferably 25000 to 50000.

The glass transition temperature of the polycarbonate resin compositionof the embodiment is preferably 95° C. to 180° C., and more preferably115° C. to 160° C.

The refractive index of the molded body produced from the polycarbonateresin composition of the embodiment (23° C., wavelength: 589 nm) ispreferably 1.640 to 1.680, and more preferably 1.650 to 1.670.

The Abbe number of the molded body produced from the polycarbonate resincomposition of the embodiment is preferably 24 or less, and morepreferably 23 or less.

Regarding optical distortion of the polycarbonate resin composition ofthe embodiment, when a molded piece of the polycarbonate resincomposition is sandwiched between two polarizing plates and lightleakage from behind is visually observed according to the crossed-Nicolmethod, it is preferred that light leakage is not significant, but isslight.

Since the molded body produced from the polycarbonate resin compositionof the embodiment exhibits low birefringence, it is suitable for astructural material of optical components such as a lens, an opticalfilm and an optical sheet. It is particularly suitable for opticalcomponents such as a lens because it has high transparency as well aslow birefringence.

To the surface of the optical molded body, a coat layer such as anantireflection layer, a hard coat layer or the like may be providedaccording to need. The antireflection layer may be either a single layeror a multilayer, and may be made of either an organic substance or aninorganic substance, but is preferably made of an inorganic substance.Specific examples thereof include oxides and fluorides such as siliconoxide, aluminium oxide, zirconium oxide, titanium oxide, cerium oxide,magnesium oxide and magnesium fluoride.

2. Polyester Resin

The polyester resin of the embodiment has a structural unit derived froma dihydroxy compound represented by general formula (1) (hereinaftersometimes referred to as “structural unit (G)”) and a structural unitderived from a dihydroxy compound represented by general formula (2)(hereinafter sometimes referred to as “structural unit (H)”). In thepolyester resin, the structural units are bound to each other via anester bond. The ester bond is also referred to as “structural unitderived from a dicarboxylic acid or a derivative thereof” or“dicarboxylic acid structural unit”.

[In formula (1), X represents a C₁₋₁₀ alkylene group.]

[In formula (2):

R¹ and R² each independently represent a hydrogen atom, a C₁₋₂₀ alkylgroup, a C₁₋₂₀ alkoxyl group, a C₅₋₂₀ cycloalkyl group, a C₅₋₂₀cycloalkoxyl group, a C₆₋₂₀ aryl group or a C₆₋₂₀ aryloxy group; and

R represents a hydrogen atom or a C₁₋₂₀ hydroxyalkyl group.]

As the compound represented by general formula (2) (excluding carboxylicacid), a compound represented by general formula (2a) and a compoundrepresented by general formula (2b) can be suitably used.

(In formula (2a), R¹ and R² are as defined with respect to formula (2)above.)

(In formula (2b), R¹ and R² are as defined with respect to formula (2)above.)

Note that details of the compound represented by general formula (2a) or(2b) are as described above.

Hereinafter, the structural unit derived from the compound representedby general formula (2a) is sometimes referred to as “structural unit(I)”.

The ratio of the total of the dihydroxy structural unit and thedicarboxylic acid structural unit in all the structural units of thepolyester resin is preferably 80 mol % or more, more preferably 90 mol %or more, and particularly preferably 100 mol %.

The polyester resin of the embodiment may contain a structural unitderived from a dihydroxy compound other than the structural units (G) to(I), and examples of the dihydroxy compound (excluding dicarboxylic acidand derivatives thereof) include alkylene glycols (e.g., linear orbranched C₂₋₁₂ alkylene glycols such as ethylene glycol, propyleneglycol, trimethylene glycol, 1,3-butanediol, tetramethylene glycol(1,4-butanediol), hexanediol, neopentylglycol, octanediol anddecanediol), and (poly)oxyalkylene glycols (e.g., diethylene glycol,triethylene glycol, dipropylene glycol).

Regarding structural units derived from these dihydroxy compounds, onetype may be contained solely, or two or more types may be contained incombination.

Moreover, in terms of physical properties, the ratio of the structuralunit derived from ethylene glycol in all the dihydroxy structural units(excluding the structural unit derived from dicarboxylic acid) ispreferably 5 to 70 mol %, and more preferably 5 to 40 mol %.

The ratio of the structural unit (G) in all the dihydroxy structuralunits (excluding the structural unit derived from dicarboxylic acid) ispreferably 5 to 95 mol %, and more preferably 60 to 95%.

The content of the structural unit (H) is preferably 95 to 5 mol %, andmore preferably 40 to 5 mol % relative to all the dihydroxy structuralunits (excluding the structural unit derived from dicarboxylic acid).The same applies to the case where the structural unit (H) is thestructural unit (I).

The molar ratio between the structural unit (G) and the structural unit(H) (G/H) is preferably 40/60 to 99/1, more preferably 60/40 to 95/5,and particularly preferably 70/30 to 90/10. The same applies to the casewhere the structural unit (H) is the structural unit (I).

The dicarboxylic acid structural unit contained in the polyester resinof the embodiment is not particularly limited, but preferred arestructural units derived from: aromatic dicarboxylic acids such asnaphthalene dicarboxylic acid, terephthalic acid, isophthalic acid,phthalic acid, 2-methylterephthalic acid, biphenyl dicarboxylic acid andtetralin dicarboxylic acid; aliphatic dicarboxylic acids such as oxalicacid, malonic acid, succinic acid, maleic acid, fumaric acid, glutaricacid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacicacid, decanedicarboxylic acid, dodecanedicarboxylic acid,cyclohexanedicarboxylic acid, decalin dicarboxylic acid, norbornanedicarboxylic acid, tricyclodecanedicarboxylic acid,pentacyclododecanedicarboxylic acid,3,9-bis(1,1-dimethyl-2-carboxyethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane,5-carboxy-5-ethyl-2-(1,1-dimethyl-2-carboxyethyl)-1,3-dioxane and dimeracid; and derivatives thereof. Examples of derivatives of thesedicarboxylic acids include esters, acid anhydrides and acid halides. Inaddition, structural units derived from a dicarboxylic acid representedby general formula (3) and a derivative thereof are also preferred.

(In the formula, Ys each independently represent a single bond, a C₁₋₂₀alkyl group, a C₁₋₂₀ alkoxyl group, a C₅₋₂₀ cycloalkyl group, a C₅₋₂₀cycloalkoxyl group, a C₆₋₂₀ aryl group or a C₆₋₂₀ aryloxy group.)

The dicarboxylic acid structural unit constituting the polyester resinof the embodiment may be composed of one of the structural unitsmentioned above, or two or more of the structural units.

The polyester resin may have a structure of either a random copolymer,block copolymer or alternating copolymer.

<Method for Producing the Polyester Resin>

The above-described polyester resin can be produced by reacting acompound by which the dicarboxylic acid structural unit is produced(e.g., dicarboxylic acids, and esters, acid anhydrides and acid halidesthereof) with a compound by which the dihydroxy structural unit isproduced (e.g., dihydroxy compounds, excluding structural units derivedfrom dicarboxylic acids). Specifically, the compound represented bygeneral formula (1), the compound represented by general formula (2)(preferably the compound represented by general formula (2a) or (2b)),and a dicarboxylic acid or a derivative thereof are reacted. Examples ofthe reaction method include various methods such as the meltpolymerization method including the transesterification method and thedirect polymerization method, the solution polymerization method and theinterfacial polymerization method. Among them, the melt polymerizationmethod not using a reaction solvent is preferred.

The dicarboxylic acid or a derivative thereof is preferably used at aratio of 0.90 to 1.01 mol relative to 1 mol of the total of thedihydroxy compounds.

The transesterification method that is one of melt polymerizationmethods is a method of obtaining a polyester by reacting a dicarboxylicacid ester with the dihydroxy compound (excluding the dicarboxylic acid)in the presence of a catalyst and performing transesterification whiledistilling away an alcohol produced, and it is generally used forsynthesis of a polyester resin.

The direct polymerization method is a method of obtaining a polyesterresin by performing a dehydration reaction of the dicarboxylic acid andthe dihydroxy compound (excluding the dicarboxylic acid) to form anester compound and then performing a transesterification reaction whiledistilling away an excess of the dihydroxy compound under reducedpressure. The direct polymerization method has the advantages thatdistillation of an alcohol is not performed unlike thetransesterification method and that an inexpensive dicarboxylic acid canbe used as a raw material. Regarding the type of the polymerizationcatalyst, the amount of the catalyst, polymerization conditions such astemperature, and additives such as a heat stabilizer, an etherificationprevention agent and a catalyst deactivator for performing these meltpolymerization methods, publicly-known methods can be referred to.

The reaction may be performed in the presence of a catalyst. As thecatalyst, various catalysts to be utilized for the production ofpolyester resins, for example, a metal catalyst can be used. As themetal catalyst, for example, a metal compound including an alkali metal,an alkaline earth metal, a transition metal, a metal belonging to Group13 of the periodic table, a metal belonging to Group 14 of the periodictable, a metal belonging to Group 15 of the periodic table or the likeis used. Examples of the metal compound include alkoxides, organic acidsalts (acetates, propionates, etc.), inorganic acid salts (borates,carbonates, etc.) and metal oxides. These catalysts may be used solely,or two or more of them may be used in combination. The amount of thecatalyst to be used may be, for example, about 0.01×10⁻⁴ to 100×10⁻⁴mol, and preferably about 0.1×10⁻⁴ to 40×10⁻⁴ mol relative to 1 mol ofthe dicarboxylic acid.

Specific examples of the alkali metal compound include sodium hydroxide,potassium hydroxide, cesium hydroxide, lithium hydroxide, sodiumhydrogen carbonate, sodium carbonate, potassium carbonate, cesiumcarbonate, lithium carbonate, sodium acetate, potassium acetate, cesiumacetate, lithium acetate, sodium stearate, potassium stearate, cesiumstearate, stearium, potassium benzoate, cesium benzoate, lithiumbenzoate, disodium hydrogen phosphate, dipotassium hydrogen phosphate,dilithium hydrogen phosphate, disodium phenyl phosphate, a disodiumsalt, dipotassium salt, dicesium salt or dilithium salt of bisphenol A,and a sodium salt, potassium salt, cesium salt or lithium salt ofphenol.

Specific examples of the alkaline earth metal compound include magnesiumhydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide,magnesium hydrogen carbonate, calcium hydrogen carbonate, strontiumhydrogen carbonate, barium hydrogen carbonate, magnesium carbonate,calcium carbonate, strontium carbonate, barium carbonate, magnesiumacetate, calcium acetate, strontium acetate, barium acetate, magnesiumstearate, calcium stearate, calcium benzoate and magnesium phenylphosphate.

As the transesterification catalyst, salts of zinc, tin, zirconium andlead are preferably used. These substances may be used solely, or two ormore of them may be used in combination.

These catalysts are used at a ratio of generally about 1×10⁻⁹ to 1×10⁻³mol, and preferably about 1×10⁻⁷ to 1×10⁻⁴ mol relative to 1 mol of thetotal of the dihydroxy compounds (excluding the dicarboxylic acid).

To the polyester resin, other resins, various additives such as anantioxidant, a mold release agent, a light stabilizer, an ultravioletabsorber, a plasticizer, an extender, a matting agent, a dryingregulator, an antistatic agent, an anti-settling agent, a surfactant, aflowability improving agent, a drying oil, a wax, a filler, a coloringagent, a reinforcing agent, a surface smoothing agent, a leveling agent,a curing reaction accelerator and a thickener, and a molding aid can beadded. Specific examples, adding amounts, etc. of these additives are asdescribed in “1. Polycarbonate resin” above. As the flowabilityimproving agent or the mold release agent, an ester of a multifunctionalalcohol and a fatty acid, particularly a stearic acid ester of glycerinis preferably added in an amount of 0.005 to 2.0 parts by weight,preferably 0.01 to 0.6 parts by weight, and more preferably 0.02 to 0.5parts by weight relative to 100 parts by weight of the polyester resin,thereby reducing troubles due to mold release failure.

Further, in order not to impair thermal stability and hydrolyticstability of the obtained polyester resin, it is preferred to remove ordeactivate the catalyst after the polymerization reaction is completed.In general, the catalyst can be deactivated by means of addition of apublicly-known acidic substance. As the acidic substance to be used fordeactivation of the catalyst, specifically, aromatic sulfonic acids suchas p-toluenesulfonic acid; aromatic sulfonic acid esters such as butylp-toluenesulfonate and hexyl p-toluenesulfonate; aromatic sulfonatessuch as dodecylbenzenesulfonic acid tetrabutylphosphonium salt; organichalides such as stearic acid chloride, benzoyl chloride andp-toluenesulfonic acid chloride; alkyl sulfates such as dimethylsulfate; organic halides such as benzyl chloride; etc. are preferablyused.

It is desired that the content of foreign materials in the polyesterresin of the embodiment is as small as possible, and filtration of amelting raw material, filtration of a catalyst solution and filtrationof a melting oligomer are preferably carried out. The mesh of the filteris preferably 7 μm or less, and more preferably 5 μm or less. Moreover,filtration of the produced resin using a polymer filter is preferablycarried out. The mesh of the polymer filter is preferably 100 μm orless, and more preferably 30 μm or less. Further, the process ofobtaining a resin pellet should definitely be carried out in a low-dustenvironment, which is preferably Class 6 or lower, and more preferablyClass 5 or lower.

<Physical Properties of the Polyester Resin>

The refractive index and the Abbe number can be measured according tothe below-described methods.

The polyester resin is dissolved in methylene chloride to produce a castfilm, and the refractive index is measured by a refractometer. The valueof the refractive index is measured at 25° C. and at 589 nm (d line),and the value of the Abbe number is calculated from refractive indexesmeasured at 656 nm (C line), 486 nm (F line) and d line.

In the polyester resin of the embodiment, the refractive index measuredin this way is preferably 1.60 or more, and more preferably 1.645 to1.70. Further, the Abbe number is preferably 21 or less, more preferably20 or less, and for example, 17 to 21.

The glass transition temperature is measured by a differential scanningcalorimeter and is not particularly limited, but is usually 110° C. orhigher, preferably 115° C. or higher, and more preferably 120° C. orhigher. When the glass transition temperature of the polyester resin iswithin the above-described ranges, an optical lens produced by using theresin is sufficiently resistant to the surface treatment including hardcoating. Note that glass transition temperatures of the polyester resinand the polyester carbonate resin can be easily set to be 110° C. orhigher by suitably selecting a conventionally-known diol or dicarboxylicacid (e.g., a diol having a cyclic acetal skeleton or aromatichydrocarbon group, a dicarboxylic acid having a naphthalene skeleton).Meanwhile, when the glass transition temperature is too high, thetemperature at the time of molding the resin must be high, and the resinitself may be thermally decomposed unpredictably. Therefore, the glasstransition temperature is preferably lower than 150° C.

<Molded Body of the Polyester Resin>

The above-described polyester resin can be used for variousapplications. For example, it can be used for an injection molded body,a sheet, a film, an extrusion molded body such as a pipe, a bottle, afoam, an adhesive material, an adhesive and a paint. More specifically,the sheet may be either a single layer or a multilayer, and the film mayalso be either a single layer or a multilayer and may be unstretched orstretched in one direction or two directions, and may be laminated on asteel plate or the like. The bottle may be either a direct blow bottleor an injection blow bottle, and may be obtained by injection molding.The foam may be either a bead foam or an extruded foam. The polyesterresin can be particularly preferably used for applications requiringhigh heat resistance and water vapor barrier properties, for example,products used in automobiles, packaging materials for import and export,electronic materials such as back sheets of solar cells, and foodpackaging materials for retorting or heating with a microwave oven.

In particular, by injection-molding the polyester resin of theembodiment into a lens shape using an injection molding machine orinjection compression molding machine, an excellent optical lens can beobtained. At the time of obtaining an optical lens, in order to avoidmixing of a foreign material therein as much as possible, the moldingenvironment must be a low-dust environment, and it is preferably Class 6or lower, and more preferably Class 5 or lower.

The optical lens obtained by molding the polyester resin is preferablyused in the form of an aspherical lens according to need. In the case ofthe aspherical lens, since the spherical aberration can be adjusted tobe substantially zero by one lens, it is not necessary to remove thespherical aberration by combining a plurality of spherical lenses, andreduction in weight and reduction in the production cost can be carriedout. Accordingly, the aspherical lens is particularly useful as a cameralens among optical lenses. The astigmatism of the aspherical lens ispreferably 0 to 15 mλ, and more preferably 0 to 10 mλ.

To the surface of the optical lens obtained by molding the polyesterresin, a coat layer such as an antireflection layer, a hard coat layeror the like may be provided according to need. The antireflection layermay be either a single layer or a multilayer, and may be made of eitheran organic substance or an inorganic substance, but is preferably madeof an inorganic substance. Specific examples thereof include oxides andfluorides such as silicon oxide, aluminium oxide, zirconium oxide,titanium oxide, cerium oxide, magnesium oxide and magnesium fluoride.

The optical lens obtained by molding the polyester resin can be used asvarious lenses such as a pickup lens, an f-θ lens and a spectacle lens,but because of its high refractive index and low Abbe number, it can beparticularly preferably used as a lens for correction of chromaticaberration. Specifically, the optical lens is preferably used as a lensof a single-lens reflex camera, a digital still camera, a video camera,a cellular phone with a camera, a disposable camera, a telescope,binoculars, a microscope, a projector or the like. When the optical lensobtained by using the polyester resin of the embodiment is a concavelens, it can be combined with another convex lens having a high Abbenumber to be used as an optical lens system having a small chromaticaberration. The Abbe number of the convex lens to be combined ispreferably 40 to 60, and more preferably 50 to 60.

3. Polyester Carbonate Resin

The polyester carbonate resin of the embodiment has a structural unit(L) derived from a dihydroxy compound represented by general formula (1)and a structural unit (M) derived from a dihydroxy compound representedby general formula (2). In the polyester carbonate resin, the structuralunits are bound to each other via a carbonate bond and an ester bond.The carbonate bond is also referred to as “structural unit derived froma carbonic acid diester”, and the ester bond is also referred to as“structural unit derived from a dicarboxylic acid or a derivativethereof” or “dicarboxylic acid structural unit”.

[In formula (1), X represents a C₁₋₁₀ alkylene group.]

[In formula (2):

R¹ and R² each independently represent a hydrogen atom, a C₁₋₂₀ alkylgroup, a C₁₋₂₀ alkoxyl group, a C₅₋₂₀ cycloalkyl group, a C₅₋₂₀cycloalkoxyl group, a C₆₋₂₀ aryl group or a C₆₋₂₀ aryloxy group; and

R represents a hydrogen atom or a C₁₋₂₀ hydroxyalkyl group.]

As the compound represented by general formula (2) (excluding carboxylicacid), a compound represented by general formula (2a) and a compoundrepresented by general formula (2b) can be suitably used.

(In formula (2a), R¹ and R² are as defined with respect to formula (2)above.)

(In formula (2b), R¹ and R² are as defined with respect to formula (2)above.)

Note that details of the compound represented by general formula (2a) or(2b) are as described above.

Hereinafter, the structural unit derived from the compound representedby general formula (2a) is sometimes referred to as “structural unit(N)”.

The ratio of the total of the dihydroxy structural unit (excluding thestructural unit derived from dicarboxylic acid), the carbonic aciddiester structural unit and the dicarboxylic acid structural unit in allthe structural units of the polyester carbonate resin is preferably 80mol % or more, more preferably 90 mol % or more, and particularlypreferably 100 mol %.

The ratio of the structural unit (L) in all the dihydroxy structuralunits (excluding the dicarboxylic acid structural unit) is preferably 5to 95 mol %.

The content of the structural unit (M) is preferably 2.5 to 47.5 mol %,and more preferably 5 to 45 mol % relative to all the dihydroxystructural units (including the dicarboxylic acid structural unit). Thesame applies to the case where the structural unit (M) is the structuralunit (N).

The molar ratio between the structural unit (L) and the structural unit(M) (L/M) is preferably 1/99 to 99/1, more preferably 20/80 to 95/5, andparticularly preferably 40/60 to 90/10. The same applies to the casewhere the structural unit (M) is the structural unit (N).

The polyester carbonate resin may have a structure of either a randomcopolymer, block copolymer or alternating copolymer.

<Structural Units Derived from Dihydroxy Compounds>

The polyester carbonate resin of the embodiment may contain a structuralunit derived from a dihydroxy compound other than the structural units(L) to (N), and examples of the dihydroxy compound (excludingdicarboxylic acid and derivatives thereof) include alkylene glycols(e.g., linear or branched C₂₋₁₂ alkylene glycols such as ethyleneglycol, propylene glycol, trimethylene glycol, 1,3-butanediol,tetramethylene glycol (1,4-butanediol), hexanediol, neopentylglycol,octanediol and decanediol), and (poly)oxyalkylene glycols (e.g.,diethylene glycol, triethylene glycol, dipropylene glycol).

Regarding structural units derived from these dihydroxy compounds, onetype may be contained solely, or two or more types may be contained incombination.

<Structural Units Derived from Carbonic Acid Diesters>

Examples of the carbonic acid diester which is a precursor of acarbonate bond include diphenyl carbonate, ditolyl carbonate,bis(chlorophenyl) carbonate, m-cresyl carbonate, dimethyl carbonate,diethyl carbonate, dibutyl carbonate and dicyclohexyl carbonate. Amongthem, diphenyl carbonate is particularly preferred. Diphenyl carbonateis used at a ratio of preferably 0.97 to 1.10 mol, and more preferably0.98 to 1.05 mol relative to 1 mol of the total of the dihydroxycompounds.

<Structural Units Derived from Dicarboxylic Acids>

The structural unit derived from the dicarboxylic acid contained in thepolyester carbonate resin of the embodiment is not particularly limited,but preferred are structural units derived from: aromatic dicarboxylicacids such as naphthalene dicarboxylic acid, terephthalic acid,isophthalic acid, phthalic acid, 2-methylterephthalic acid, biphenyldicarboxylic acid and tetralin dicarboxylic acid; aliphatic dicarboxylicacids such as oxalic acid, malonic acid, succinic acid, maleic acid,fumaric acid, glutaric acid, adipic acid, pimelic acid, suberic acid,azelaic acid, sebacic acid, decanedicarboxylic acid,dodecanedicarboxylic acid, cyclohexanedicarboxylic acid, decalindicarboxylic acid, norbornane dicarboxylic acid,tricyclodecanedicarboxylic acid, pentacyclododecanedicarboxylic acid,3,9-bis(1,1-dimethyl-2-carboxyethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane,5-carboxy-5-ethyl-2-(1,1-dimethyl-2-carboxyethyl)-1,3-dioxane and dimeracid; and derivatives thereof. Examples of derivatives of thesedicarboxylic acids include esters, acid anhydrides and acid halides. Inaddition, structural units derived from a dicarboxylic acid representedby general formula (3) and a derivative thereof are also preferred.

(In the formula, Ys each independently represent a single bond, a C₁₋₂₀alkyl group, a C₁₋₂₀ alkoxyl group, a C₅₋₂₀ cycloalkyl group, a C₅₋₂₀cycloalkoxyl group, a C₆₋₂₀ aryl group or a C₆₋₂₀ aryloxy group.)

The dicarboxylic acid structural unit may be composed of one of thestructural units mentioned above, or two or more of the structuralunits.

<Method for Producing the Polyester Carbonate Resin>

The above-described polyester carbonate resin can be produced byperforming a transesterification reaction of a compound by which thecarbonic acid diester structural unit is produced, a compound by whichthe dicarboxylic acid structural unit is produced and a compound bywhich the dihydroxy structural unit is produced in a molten state in thepresence of the catalyst. Specifically, the compound represented bygeneral formula (1), the compound represented by general formula (2)(preferably the compound represented by general formula (2a) or (2b)), adicarboxylic acid or a derivative thereof, and a carbonic acid diesterare reacted. Examples of the reaction method include various methodssuch as the melt polymerization method including the transesterificationmethod and the direct polymerization method, the solution polymerizationmethod and the interfacial polymerization method. Among them, the meltpolymerization method not using a reaction solvent is preferred.

The carbonic acid diester is used at a ratio of preferably 0.97 to 1.10mol, and more preferably 0.98 to 1.05 mol relative to 1 mol of the totalof the dihydroxy compounds. Further, the dicarboxylic acid or aderivative thereof is used at a ratio of preferably 0.01 to 0.20 mol,and more preferably 0.05 to 0.15 mol relative to 1 mol of the total ofthe dihydroxy compounds (excluding the dicarboxylic acid).

The transesterification method that is one of melt polymerizationmethods is a method of obtaining a polyester by reacting a dicarboxylicacid ester with the dihydroxy compound (excluding the dicarboxylic acid)in the presence of a catalyst and performing transesterification whiledistilling away an alcohol produced, and it is generally used forsynthesis of a polyester resin.

The direct polymerization method is a method of obtaining a polyesterresin by performing a dehydration reaction of the dicarboxylic acid andthe dihydroxy compound (excluding the dicarboxylic acid) to form anester compound and then performing a transesterification reaction whiledistilling away an excess of the dihydroxy compound under reducedpressure. The direct polymerization method has the advantages thatdistillation of an alcohol is not performed unlike thetransesterification method and that an inexpensive dicarboxylic acid canbe used as a raw material. Regarding the type of the polymerizationcatalyst, the amount of the catalyst, polymerization conditions such astemperature, and additives such as a heat stabilizer, an etherificationprevention agent and a catalyst deactivator for performing these meltpolymerization methods, publicly-known methods can be referred to.

The reaction may be performed in the presence of a catalyst. As thecatalyst, various catalysts to be utilized for the production ofpolyester carbonate resins, for example, a metal catalyst can be used.As the metal catalyst, for example, a metal compound including an alkalimetal, an alkaline earth metal, a transition metal, a metal belonging toGroup 13 of the periodic table, a metal belonging to Group 14 of theperiodic table, a metal belonging to Group 15 of the periodic table orthe like is used. Examples of the metal compound include alkoxides,organic acid salts (acetates, propionates, etc.), inorganic acid salts(borates, carbonates, etc.) and metal oxides. These catalysts may beused solely, or two or more of them may be used in combination. Theamount of the catalyst to be used may be, for example, about 0.01×10⁻⁴to 100×10⁻⁴ mol, and preferably about 0.1×10⁻⁴ to 40×10⁻⁴ mol relativeto 1 mol of the dicarboxylic acid component.

Specific examples of the alkali metal compound include sodium hydroxide,potassium hydroxide, cesium hydroxide, lithium hydroxide, sodiumhydrogen carbonate, sodium carbonate, potassium carbonate, cesiumcarbonate, lithium carbonate, sodium acetate, potassium acetate, cesiumacetate, lithium acetate, sodium stearate, potassium stearate, cesiumstearate, stearium, potassium benzoate, cesium benzoate, lithiumbenzoate, disodium hydrogen phosphate, dipotassium hydrogen phosphate,dilithium hydrogen phosphate, disodium phenyl phosphate, a disodiumsalt, dipotassium salt, dicesium salt or dilithium salt of bisphenol A,and a sodium salt, potassium salt, cesium salt or lithium salt ofphenol.

Specific examples of the alkaline earth metal compound include magnesiumhydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide,magnesium hydrogen carbonate, calcium hydrogen carbonate, strontiumhydrogen carbonate, barium hydrogen carbonate, magnesium carbonate,calcium carbonate, strontium carbonate, barium carbonate, magnesiumacetate, calcium acetate, strontium acetate, barium acetate, magnesiumstearate, calcium stearate, calcium benzoate and magnesium phenylphosphate.

As the transesterification catalyst, salts of zinc, tin, zirconium andlead are preferably used. These substances may be used solely, or two ormore of them may be used in combination.

These catalysts are used at a ratio of generally 1×10⁻⁹ to 1×10⁻³ mol,and preferably 10⁻⁷ to 10⁻⁴ mol relative to 1 mol of the total of thedihydroxy compounds (excluding the dicarboxylic acid).

To the polyester carbonate resin, other resins, various additives suchas an antioxidant, a mold release agent, a light stabilizer, anultraviolet absorber, a plasticizer, an extender, a matting agent, adrying regulator, an antistatic agent, an anti-settling agent, asurfactant, a flowability improving agent, a drying oil, a wax, afiller, a coloring agent, a reinforcing agent, a surface smoothingagent, a leveling agent, a curing reaction accelerator and a thickener,and a molding aid can be added. Specific examples, adding amounts, etc.of these additives are as described in “1. Polycarbonate resin” above.As the flowability improving agent or the mold release agent, an esterof a multifunctional alcohol and a fatty acid, particularly a stearicacid ester of glycerin is preferably added in an amount of 0.005 to 2.0parts by weight, preferably 0.01 to 0.6 parts by weight, and morepreferably 0.02 to 0.5 parts by weight relative to 100 parts by weightof the polyester carbonate resin, thereby reducing troubles due to moldrelease failure.

Further, in order not to impair thermal stability and hydrolyticstability of the obtained polyester carbonate resin, it is preferred toremove or deactivate the catalyst after the polymerization reaction iscompleted. In general, the catalyst can be deactivated by means ofaddition of a publicly-known acidic substance. As the acidic substanceto be used for deactivation of the catalyst, specifically, aromaticsulfonic acids such as p-toluenesulfonic acid; aromatic sulfonic acidesters such as butyl p-toluenesulfonate and hexyl p-toluenesulfonate;aromatic sulfonates such as dodecylbenzenesulfonic acidtetrabutylphosphonium salt; organic halides such as stearic acidchloride, benzoyl chloride and p-toluenesulfonic acid chloride; alkylsulfates such as dimethyl sulfate; organic halides such as benzylchloride; etc. are preferably used.

It is desired that the content of foreign materials in the polyestercarbonate resin of the embodiment is as small as possible, andfiltration of a melting raw material, filtration of a catalyst solutionand filtration of a melting oligomer are preferably carried out. Themesh of the filter is preferably 7 μm or less, and more preferably 5 μmor less. Moreover, filtration of the produced resin using a polymerfilter is preferably carried out. The mesh of the polymer filter ispreferably 100 μm or less, and more preferably 30 μm or less. Further,the process of obtaining a resin pellet should definitely be carried outin a low-dust environment, which is preferably Class 6 or lower, andmore preferably Class 5 or lower.

<Physical Properties of the Polyester Carbonate Resin>

The refractive index and the Abbe number can be measured according tothe below-described measurement methods.

The polyester carbonate resin is dissolved in methylene chloride toproduce a cast film, and the refractive index is measured by arefractometer. The value of the refractive index is measured at 25° C.and at 589 nm (d line), and the value of the Abbe number is calculatedfrom refractive indexes measured at 656 nm (C line), 486 nm (F line) andd line.

In the polyester carbonate resin of the embodiment, the refractive indexmeasured in this way is preferably 1.60 or more, and more preferably1.645 to 1.665. Further, the Abbe number is preferably 24 or less, morepreferably 21 or less, and for example, 18 to 24.

The glass transition temperature is measured by a differential scanningcalorimeter and is not particularly limited, but is usually 110° C. orhigher, preferably 115° C. or higher, and more preferably 120° C. orhigher. When the glass transition temperature of the polyester carbonateresin is within the above-described ranges, an optical lens produced byusing the resin is sufficiently resistant to the surface treatmentincluding hard coating. Note that glass transition temperatures of thepolyester resin and the polyester carbonate resin can be easily set tobe 110° C. or higher by suitably selecting a conventionally-known diolor dicarboxylic acid (e.g., a diol having a cyclic acetal skeleton oraromatic hydrocarbon group, a dicarboxylic acid having a naphthaleneskeleton). Meanwhile, when the glass transition temperature is too high,the temperature at the time of molding the resin must be high, and theresin itself may be thermally decomposed unpredictably. Therefore, theglass transition temperature is preferably lower than 150° C.

The polystyrene equivalent weight-average molecular weight (Mw) ispreferably 10000 to 100000, and more preferably 20000 to 50000.

When Mw is less than 10000, a resin molded body obtained tends to befragile and therefore it is undesirable. When Mw is more than 100000,the melt viscosity increases, resulting in difficulty in taking out aresin from a mold at the time of molding, and in addition, theflowability is reduced, resulting in difficulty in injection molding ina molten state, and therefore it is undesirable.

The color phase of the solution (brightness; L value) is measuredaccording to the method shown in the Examples, and is preferably 88 ormore, and more preferably 95 to 99. When the L value is less than 88,the resin is more strongly colored, resulting in difficulty in usethereof as an optical material, and therefore it is undesirable.

The limiting viscosity and the semicrystallization time of the polyestercarbonate resin of the embodiment are the same as those described in “2.Polyester resin” above.

Further, the resin of the embodiment preferably satisfies thebelow-described physical properties (1) and (2) simultaneously.

(1) According to the method for measuring a plastic transitiontemperature in accordance with JIS K7121, the measurement value of themiddle point glass-transition temperature is 120° C. or higher.

(2) The measurement value of the limiting viscosity at 25° C. using amixed solvent of phenol and 1,1,2,2-tetrachloroethane with a mass ratioof 6:4 is 0.2 to 1.0 dl/g.

<Molded Body of the Polyester Carbonate Resin>

The above-described polyester carbonate resin can be used for variousapplications. For example, it can be used for an injection molded body,a sheet, a film, an extrusion molded body such as a pipe, a bottle, afoam, an adhesive material, an adhesive and a paint. More specifically,the sheet may be either a single layer or a multilayer, and the film mayalso be either a single layer or a multilayer and may be unstretched orstretched in one direction or two directions, and may be laminated on asteel plate or the like. The bottle may be either a direct blow bottleor an injection blow bottle, and may be obtained by injection molding.The foam may be either a bead foam or an extruded foam. The polyesterresin can be particularly preferably used for applications requiringhigh heat resistance and water vapor barrier properties, for example,products used in automobiles, packaging materials for import and export,electronic materials such as back sheets of solar cells, and foodpackaging materials for retorting or heating with a microwave oven.

In particular, by injection-molding the polyester carbonate resin of theembodiment into a lens shape using an injection molding machine orinjection compression molding machine, an excellent optical lens can beobtained. At the time of obtaining an optical lens, in order to avoidmixing of a foreign material therein as much as possible, the moldingenvironment must be a low-dust environment, and it is preferably Class 6or lower, and more preferably Class 5 or lower.

The optical lens obtained by molding the polyester carbonate resin ispreferably used in the form of an aspherical lens according to need. Inthe case of the aspherical lens, since the spherical aberration can beadjusted to be substantially zero by one lens, it is not necessary toremove the spherical aberration by combining a plurality of sphericallenses, and reduction in weight and reduction in the production cost canbe carried out. Accordingly, the aspherical lens is particularly usefulas a camera lens among optical lenses. The astigmatism of the asphericallens is preferably 0 to 15 mλ, and more preferably 0 to 10 mλ.

To the surface of the optical lens obtained by molding the polyestercarbonate resin, a coat layer such as an antireflection layer, a hardcoat layer or the like may be provided according to need. Theantireflection layer may be either a single layer or a multilayer, andmay be made of either an organic substance or an inorganic substance,but is preferably made of an inorganic substance. Specific examplesthereof include oxides and fluorides such as silicon oxide, aluminiumoxide, zirconium oxide, titanium oxide, cerium oxide, magnesium oxideand magnesium fluoride.

The optical lens obtained by molding the polyester carbonate resin canbe used as various lenses such as a pickup lens, an f-θ lens and aspectacle lens, but because of its high refractive index and low Abbenumber, it can be particularly preferably used as a lens for correctionof chromatic aberration. Specifically, the optical lens is preferablyused as a lens of a single-lens reflex camera, a digital still camera, avideo camera, a cellular phone with a camera, a disposable camera, atelescope, binoculars, a microscope, a projector or the like. When theoptical lens obtained by using the polyester carbonate resin of theembodiment is a concave lens, it can be combined with another convexlens having a high Abbe number to be used as an optical lens systemhaving a small chromatic aberration. The Abbe number of the convex lensto be combined is preferably 40 to 60, and more preferably 50 to 60.

EXAMPLES

Hereinafter, the present invention will be specifically described by wayof examples, but the present invention is not limited thereto.

1. Polycarbonate Resin

(A) Examples of Polycarbonate Resin

Measurement values of polycarbonate resins in the Examples were measuredusing the below-described methods and apparatuses.

1) Polystyrene equivalent weight-average molecular weight (Mw): Usinggel permeation chromatograph (GPC) and tetrahydrofuran as a developingsolvent, a calibration curve was produced using a standard polystyrenehaving an already-known molecular weight (molecular weightdistribution=1). Based on this calibration curve, Mw was calculated fromthe GPC retention time.[Measurement Conditions]Apparatus: HLC-8320GPC manufactured by Tosoh CorporationColumn:

Guard column: TSKguardcolumn SuperMPHZ-M×1

Analysis column: TSKgel SuperMultiporeHZ-M×3

Solvent: tetrahydrofuran

Injection amount: 10 μL

Sample concentration: 0.2 w/v % tetrahydrofuran solution

Flow rate of solvent: 0.35 ml/min

Measurement temperature: 40° C.

Detector: RI

2) Refractive index (nD): The refractive index of a film having athickness of 0.1 mm made of the polycarbonate resin produced in theExamples was measured according to the method of JIS-K-7142 using anAbbe's refractometer (23° C., wavelength: 589 nm). 3) Abbe number (v):Refractive indexes of a film having a thickness of 0.1 mm made of thepolycarbonate resin produced in the Examples were measured at 23° C. andat wavelengths of 486 nm, 589 nm and 656 nm using an Abbe'srefractometer, and the Abbe number was calculated using thebelow-described formula:v=(nD−1)/(nF−nC)

nD: refractive index at a wavelength of 589 nm

nC: refractive index at a wavelength of 656 nm

nF: refractive index at a wavelength of 486 nm

4) Glass transition temperature (Tg): It was measured using adifferential scanning calorimeter (DSC) (measurement apparatus: DSC7000Xmanufactured by Hitachi High-Tech Science Corporation).

5) Thermal decomposition initiation temperature (Td): The temperature atwhich the weight decreased by 5% was measured in an air stream using adifferential thermal balance (TG-DTA). The temperature raising rate was10° C./min (measurement apparatus: Simultaneous ThermogravimetricAnalyzer STA7000 manufactured by Hitachi High-Tech Science Corporation).6) Orientation birefringence (Δn): A cast film having a thickness of 0.1mm was cut into a 5.0×5.0 cm square; after that, both the ends of thefilm were sandwiched between chucks (distance between the chucks: 3.0cm); the film was stretched 1.5-fold at a temperature of Tg of thepolycarbonate resin+5° C.; the phase difference (Re) at 589 nm wasmeasured using an ellipsometer M-220 manufacture by JASCO Corporation;and after that, the orientation birefringence (Δn) was obtained from thebelow-described formula:Δn=Re/d

Δn: orientation birefringence

Re: phase difference

d: thickness

Further, regarding the birefringence signs, the direction in which therefractive index becomes maximum in the surface of the above-describedstretched film was obtained using an ellipsometer M-220 manufacture byJASCO Corporation, and the birefringence sign was judged from therelationship between the direction and the stretching direction.

In the case where the birefringence sign is positive: the stretchingdirection is a direction in which the refractive index becomes maximumin the film surface.

In the case where the birefringence sign is negative: the stretchingdirection is a direction perpendicular to a direction in which therefractive index becomes maximum in the film surface.

7) Total light transmittance: The total light transmittance of a filmhaving a thickness of 0.1 mm made of the polycarbonate resin produced inthe Examples was measured according to the method of JIS-K-7361-1 usinga turbidimeter NDH2000 manufactured by Nippon Denshoku Industries Co.,Ltd.8) Amounts of residual phenol and residual diphenyl carbonate: 1.0 g ofa polycarbonate resin was precisely weighed and dissolved in 10 ml ofdichloromethane, and the mixture was gradually added to 100 ml ofmethanol with stirring to reprecipitate the resin. After the mixture wassufficiently stirred, a precipitate was separated by filtration, afiltrate was concentrated by an evaporator, and 1.0 g of a standardsubstance solution was precisely weighed and added to the obtainedsolid. 1 g of chloroform was further added thereto, and the dilutedsolution was quantified by means of GC-MS.Standard substance solution: solution of 200 ppm trimethylol phenol inchloroformMeasurement apparatus (GC-MS): Agilent HP6890/5973MSDColumn: capillary column DB-5MS, 30 m×0.25 mm I.D., film thickness: 0.5μmTemperature raising conditions: 50° C. (5 min hold) to 300° C. (15 minhold), 10° C./minTemperature of inlet: 300° C., Amount of injection: 1.0 μl (split ratio:25)Ionization method: EI methodCarrier gas: He, 1.0 ml/minAux temperature: 300° C.Mass scanning range: 33 to 700

Example of the Production of Polycarbonate Resin (1) Example 1

13.4 g (0.035 mol) of 2,2′-bis(2-hydroxyethoxy)-1,1′-binaphthalene(hereinafter sometimes abbreviated as “BHEBN”), 35.6 g (0.081 mol) of9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene (hereinafter sometimesabbreviated as “BPEF”), 25.0 g (0.117 mol) of diphenyl carbonate(hereinafter sometimes abbreviated as “DPC”) and 8.8×10⁵ g (1.0×10⁻⁶mol) of sodium hydrogen carbonate were put into a 300 ml four-neck flaskequipped with a stirrer and a distillation apparatus, and it was heatedto 180° C. under nitrogen atmosphere (760 mmHg). 10 minutes after thestart of heating, complete dissolution of the raw materials wasconfirmed. After that, stirring was performed for 110 minutes under thesame conditions. After that, the pressure reducing degree was adjustedto 200 mmHg, and simultaneously, the temperature was increased to 200°C. at a rate of 60° C./hr. During this, the start of distillation ofby-produced phenol was confirmed. After that, the temperature was keptfor 20 minutes to perform a reaction. Further, the temperature wasincreased to 230° C. at a rate of 75° C./hr, and 10 minutes after theend of the increase of the temperature, the temperature was kept whilethe pressure reducing degree was adjusted to 1 mmHg or less over 1 hour.After that, the temperature was increased to 240° C. at a rate of 60°C./hr, and a reaction was performed with stirring for 30 minutes. Afterthe reaction was completed, nitrogen was blown into the reactor toadjust the pressure to ordinary pressure, and a polycarbonate resinproduced was taken out therefrom. In the polycarbonate resin, the amountof residual phenol was 150 ppm, and the amount of residual DPC was 120ppm.

Example 2

The operation was carried out in a manner similar to that in Example 1,except that the amounts of BHEBN, BPEF, DPC and sodium hydrogencarbonate were changed to 17.1 g (0.046 mol), 30.1 g (0.069 mol), 25.0 g(0.117 mol) and 8.7×10⁻⁵ g (1.0×10⁻⁶ mol), respectively, and apolycarbonate resin produced was taken out. In the polycarbonate resin,the amount of residual phenol was 60 ppm, and the amount of residual DPCwas 250 ppm.

Example 3

The operation was carried out in a manner similar to that in Example 1,except that the amounts of BHEBN, BPEF, DPC and sodium hydrogencarbonate were changed to 30.0 g (0.080 mol), 15.1 g (0.034 mol), 25.0 g(0.117 mol) and 8.7×10⁵ g (1.0×10⁻⁶ mol), respectively, and apolycarbonate resin produced was taken out. In the polycarbonate resin,the amount of residual phenol was 120 ppm.

Example 4

The operation was carried out in a manner similar to that in Example 1,except that the amounts of BHEBN, BPEF, DPC and sodium hydrogencarbonate were changed to 38.9 g (0.104 mol), 5.07 g (0.012 mol), 25.0 g(0.117 mol) and 1.1×10⁻⁴ g (1.3×10⁻⁶ mol), respectively, and apolycarbonate resin produced was taken out. In the polycarbonate resin,the amount of residual phenol was 100 ppm.

Reference Example 1

The operation was carried out in a manner similar to that in Example 1,except that the time of stirring performed under the same conditionsafter heating to 180° C. under nitrogen atmosphere (760 mmHg) andconfirming complete dissolution of the raw materials was reduced from110 minutes to 30 minutes and that the final pressure reducing degreewas adjusted to 50 mmHg, and a polycarbonate resin produced was takenout. In the polycarbonate resin, the amount of residual phenol was 3500ppm, and the amount of residual DPC was 1200 ppm.

Comparative Example 1

As a polycarbonate resin made of bisphenol A (hereinafter sometimesabbreviated as “BPA”), “Iupilon H-4000” (trade name, manufactured byMitsubishi Engineering-Plastics Corporation, Mw=33,000, Tg=148° C.) wasused.

Example (1) of the Production of Optical Film

Each of the polycarbonate resins obtained in Examples 1-4, ReferenceExample 1 and Comparative Example 1 was dissolved in methylene chlorideto prepare a resin solution in which the solid component concentrationwas 5.3 wt %. This resin solution was poured into a mold for theproduction of a cast film, and released and dried after volatilizationof methylene chloride, thereby preparing a cast film having a thicknessof 0.1 mm. The refractive index (nD), the Abbe number (v) and the totallight transmittance of the cast film were evaluated. Further, theobtained cast film was stretched 1.5-fold at a temperature of Tg+5° C.to evaluate the orientation birefringence (Δn).

Note that it was impossible to prepare a cast film when using thepolycarbonate resin obtained in Reference Example 1 because it had a lowmolecular weight and was fragile.

In addition, the polystyrene equivalent weight-average molecular weight(Mw), the glass transition temperature (Tg) and the thermaldecomposition initiation temperature (Td) of each of the resins obtainedin the above-described Examples, Reference Example and ComparativeExample were measured. The obtained values are shown in Table 1.Further, the birefringence is shown in Table 2, and evaluation criteriaof the orientation birefringence (Δn) in Table 2 are shown in Table 3.

TABLE 1 Physical properties Composition ratio Total light Amount ofBHEBN BPEF BPA Tg Td transmittance residual phenol mol % mol % mol % Mw° C. ° C. nD ν % ppm Example 1 30 70 — 105000 141 368 1.647 22 89 150Example 2 40 60 — 44000 135 366 1.65  22 89 60 Example 3 70 30 — 56000123 363 1.659 21 88 120 Example 4 90 10 — 53000 120 361 1.655 20 88 100Reference 30 70 — 4000 75 324 — — — 3500 Example 1 Comparative — — 10033000 148 — 1.589 30 91 0 Example 1

TABLE 2 Birefringence Composition ratio Orientation BHEBN BPEF BPAbirefringence birefringence mol % mol % mol % (Δn) sign Example 1 30 70— 0.28 × 10⁻³ negative Example 2 40 60 — 0.11 × 10⁻³ negative Example 370 30 — 0.02 × 10⁻³ negative Example 4 90 10 — 0.28 × 10⁻³ positiveReference 30 70 — — — Example 1 Comparative — — 100  9.5 × 10⁻³ positiveExample 1

TABLE 3 Orientation birefringence Δn (×10⁻³) Evaluation 0 to 0.1Extremely very small More than 0.1 to 0.4 Very small More than 0.4 to1.0 Small More than 1.0 Large

Example of the Production of Polycarbonate Resin (2) Example 7

3.44 g (0.009 mol) of 2,2′-bis(2-hydroxyethoxy)-1,1′-binaphthalene(hereinafter sometimes abbreviated as “BHEBN”), 48.9 g (0.083 mol) of9,9-bis(4-(2-hydroxyethoxy)-3-phenylphenyl)fluorene (hereinaftersometimes abbreviated as “BEPF”), 20.3 g (0.095 mol) of diphenylcarbonate (hereinafter sometimes abbreviated as “DPC”) and 1.5×10⁻⁴ g(1.8×10⁻⁶ mol) of sodium hydrogen carbonate were put into a 300 mlfour-neck flask equipped with a stirrer and a distillation apparatus,and it was heated to 180° C. under nitrogen atmosphere (760 mmHg). 10minutes after the start of heating, complete dissolution of the rawmaterials was confirmed. After that, stirring was performed for 110minutes under the same conditions. After that, the pressure reducingdegree was adjusted to 200 mmHg, and simultaneously, the temperature wasincreased to 200° C. at a rate of 60° C./hr. During this, the start ofdistillation of by-produced phenol was confirmed. After that, thetemperature was kept for 20 minutes to perform a reaction. Further, thetemperature was increased to 230° C. at a rate of 75° C./hr, and 10minutes after the end of the increase of the temperature, thetemperature was kept while the pressure reducing degree was adjusted to1 mmHg or less over 1 hour. After that, the temperature was increased to240° C. at a rate of 60° C./hr, and a reaction was performed withstirring for 30 minutes. After the reaction was completed, nitrogen wasblown into the reactor to adjust the pressure to ordinary pressure, anda polycarbonate resin produced was taken out therefrom.

Example 8

The operation was carried out in a manner similar to that in Example 7,except that the amounts of BHEBN, BEPF, DPC and sodium hydrogencarbonate were changed to 5.17 g (0.014 mol), 19.0 g (0.032 mol), 10.0 g(0.047 mol) and 9.7×10⁻⁵ g (1.2×10⁻⁶ mol), respectively, and apolycarbonate resin produced was taken out.

Example 9

The operation was carried out in a manner similar to that in Example 7,except that the amounts of BHEBN, BEPF, DPC and sodium hydrogencarbonate were changed to 13.8 g (0.037 mol), 32.6 g (0.055 mol), 20.0 g(0.093 mol) and 1.5×10⁻⁴ g (1.8×10⁻⁶ mol), respectively, and apolycarbonate resin produced was taken out.

Example 10

The operation was carried out in a manner similar to that in Example 7,except that the amounts of BHEBN, BEPF, DPC and sodium hydrogencarbonate were changed to 24.4 g (0.065 mol), 16.5 g (0.028 mol), 20.2 g(0.094 mol) and 1.6×10⁻⁴ g (1.9×10⁻⁶ mol), respectively, and apolycarbonate resin produced was taken out.

Example 11

The operation was carried out in a manner similar to that in Example 7,except that the amounts of BHEBN, BEPF, DPC and sodium hydrogencarbonate were changed to 31.0 g (0.083 mol), 5.4 g (0.009 mol), 20.0 g(0.093 mol) and 1.5×10⁻⁴ g (1.8×10⁻⁶ mol), respectively, and apolycarbonate resin produced was taken out.

Comparative Example 2

As a polycarbonate resin made of bisphenol A (hereinafter sometimesabbreviated as “BPA”), “Iupilon H-4000” (trade name, manufactured byMitsubishi Engineering-Plastics Corporation, Mw=33,000, Tg=148° C.) wasused.

Reference Example 2

24.4 g (0.065 mol) of BHEBN, 16.5 g (0.028 mol) of BPEF, 20.2 g (0.094mol) of DPC and 1.6×10⁻⁴ g (1.9×10⁻⁶ mol) of sodium hydrogen carbonatewere put into a 300 ml four-neck flask equipped with a stirrer and adistillation apparatus, and it was heated to 180° C. under nitrogenatmosphere (760 mmHg). 10 minutes after the start of heating, completedissolution of the raw materials was confirmed. After that, stirring wasperformed for 20 minutes under the same conditions. After that, thepressure reducing degree was adjusted to 200 mmHg, and simultaneously,the temperature was increased to 200° C. at a rate of 60° C./hr. Duringthis, the start of distillation of by-produced phenol was confirmed.After that, the temperature was kept for 20 minutes to perform areaction. Further, the temperature was increased to 230° C. at a rate of75° C./hr, and 10 minutes after the end of the increase of thetemperature, the temperature was kept while the pressure reducing degreewas adjusted to 1 mmHg or less over 1 hour. After that, the temperaturewas increased to 240° C. at a rate of 60° C./hr, and a reaction wasperformed with stirring for 30 minutes. After the reaction wascompleted, nitrogen was blown into the reactor to adjust the pressure toordinary pressure, and a polycarbonate resin produced was taken outtherefrom.

<Example of the Production of Optical Film (2)>

Each of the polycarbonate resins obtained in Examples 7-11, ComparativeExample 2 and Reference Example 2 was dissolved in methylene chloride toprepare a resin solution in which the solid component concentration was5.3 wt %. This resin solution was poured into a mold for the productionof a cast film, and released and dried after volatilization of methylenechloride, thereby preparing a cast film having a thickness of 0.1 mm.The refractive index (nD), the Abbe number (v) and the total lighttransmittance of the cast film were evaluated. Further, the obtainedcast film was stretched 1.5-fold at a temperature of Tg+5° C. toevaluate the orientation birefringence (Δn).

Note that it was impossible to prepare a cast film when using thepolycarbonate resin obtained in Reference Example 2 because it had a lowmolecular weight and was fragile.

In addition, the polystyrene equivalent weight-average molecular weight(Mw), the glass transition temperature (Tg) and the thermaldecomposition initiation temperature (Td) of each of the resins obtainedin the above-described Examples, Comparative Example and ReferenceExample were measured. The obtained values are shown in Table 4.Further, the birefringence is shown in Table 5, and evaluation criteriaof the orientation birefringence (Δn) in Table 5 are shown in Table 6.

TABLE 4 Physical properties Composition ratio Total light BHEBN BEPF BPAMw Tg Td nD ν transmittance mol % mol % mol % — ° C. ° C. — — % Example7 10 90 — 36000 152 364 1.656 21 87 Example 8 30 70 — 47000 145 3671.658 21 87 Example 9 40 60 — 50000 141 367 1.659 21 87 Example 10 70 30— 39000 129 372 1.663 20 86 Example 11 90 10 — 38000 120 373 1.666 19 86Comparative — — 100 33000 148 — 1.586 30 91 Example 2 Reference 70 30 —2800 54 314 — — — Example 2

TABLE 5 Birefringence Composition ratio Orientation BHEBN BEPF BPAbirefringence birefringence mol % mol % mol % (Δn) sign Example 7 10 90— 0.60 × 10⁻³ negative Example 8 30 70 — 0.41 × 10⁻³ negative Example 940 60 — 0.29 × 10⁻³ negative Example 10 70 30 — 0.02 × 10⁻³ positiveExample 11 90 10 — 0.21 × 10⁻³ positive Comparative — — 100  9.5 × 10⁻³positive Example 2 Reference 70 30 — — — Example 2

TABLE 6 Orientation birefringence Δn (×10⁻³) Evaluation 0 to 0.1Extremely very small More than 0.1 to 0.4 Very small More than 0.4 to1.0 Small More than 1.0 Large(B) Examples of Polycarbonate Resin Composition

Measurement values of polycarbonate resin compositions in the Exampleswere measured using the below-described methods and apparatuses.

1) Polystyrene equivalent weight-average molecular weight (Mw): Usinggel permeation chromatograph (GPC) and tetrahydrofuran as a developingsolvent, a calibration curve was produced using a standard polystyrenehaving an already-known molecular weight (molecular weightdistribution=1). Based on this calibration curve, Mw was calculated fromthe GPC retention time.[Measurement conditions]Apparatus: HLC-8320GPC manufactured by Tosoh CorporationColumn:

Guard column: TSKguardcolumn SuperMPHZ-M×1

Analysis column: TSKgel SuperMultiporeHZ-M×3

Solvent: tetrahydrofuran

Injection amount: 10 μL

Sample concentration: 0.2 w/v % tetrahydrofuran solution

Flow rate of solvent: 0.35 ml/min

Measurement temperature: 40° C.

Detector: RI

2) Glass transition temperature (Tg): It was measured using adifferential scanning calorimeter (DSC) (measurement apparatus: DSC7000Xmanufactured by Hitachi High-Tech Science Corporation).

3) Refractive index (nD): The polycarbonate resin composition waspress-molded to obtain a molded body (cuboid of 3 mm (thickness)×8 mm×8mm), and the refractive index of the molded body was measured using arefractometer (KPR-200) manufactured by Shimadzu Corporation (23° C.,wavelength: 589 nm).4) Abbe number (v): The polycarbonate resin composition was press-moldedto obtain a molded body (cuboid of 3 mm (thickness)×8 mm×8 mm), andrefractive indexes of the molded body were measured at wavelengths of486 nm, 589 nm and 656 nm using a refractometer (KPR-200) manufacturedby Shimadzu Corporation. Further, the Abbe number was calculated usingthe below-described formula:v=(nD−1)/(nF−nC)

nD: refractive index at a wavelength of 589 nm

nC: refractive index at a wavelength of 656 nm

nF: refractive index at a wavelength of 486 nm

5) Optical distortion: A molded piece having a thickness of 3 mm made ofthe polycarbonate resin composition was sandwiched between twopolarizing plates, and light leakage from behind was visually observedaccording to the crossed-Nicol method to make evaluation. Morespecifically, each of the polycarbonate resin compositions obtained inExamples 13-17 and Comparative Examples 3-5 was injection-molded toobtain a molded piece having a diameter of 50 mm and a thickness of 3 mmusing an injection molding machine ROBOSHOT S-2000i30A manufactured byFANUC Corporation. The molded piece was sandwiched between twopolarizing plates, and light leakage from behind was visually observedaccording to the crossed-Nicol method to make evaluation. Rating in theevaluation is as follows:A: Slight light leakage was observed.B: Light leakage was observed.C: Significant light leakage was observed.

(Synthesis Example 1: Production of Polycarbonate Resin (A1))

20.0 kg (53.4 mol) of 2,2′-bis(2-hydroxyethoxy)-1,1′-binaphthalene, 11.7kg (54.5 mol) of diphenyl carbonate and 6.7×10⁻² g (8.0×10⁻⁴ mol) ofsodium hydrogen carbonate were put into a 50 L reactor equipped with astirrer and a distillation apparatus, and it was heated to 200° C. over1 hour under nitrogen atmosphere (760 mmHg) and stirred. After that,stirring was performed for 110 minutes under the same conditions. Afterthat, the pressure reducing degree was adjusted to 200 mmHg over 20minutes, and conditions were kept at 200° C. and 200 mmHg for 40 minutesto perform a transesterification reaction. Further, the temperature wasincreased to 230° C. at a rate of 45° C./hr, and conditions were kept at230° C. and 200 mmHg for 10 minutes. After that, the pressure reducingdegree was adjusted to 150 mmHg over 20 minutes, and conditions werekept at 230° C. and 150 mmHg for 10 minutes. After that, the pressurereducing degree was adjusted to 120 mmHg over 10 minutes, and conditionswere kept at 230° C. and 120 mmHg for 70 minutes. After that, thepressure reducing degree was adjusted to 100 mmHg over 10 minutes, andconditions were kept at 230° C. and 100 mmHg for 10 minutes. Further,the pressure reducing degree was adjusted to 1 mmHg or less over 40minutes, and stirring was performed under conditions of 230° C. and 1mmHg or less for 30 minutes to perform a polymerization reaction. Afterthe reaction was completed, nitrogen was blown into the reactor toincrease the pressure, and a polycarbonate resin produced was taken outtherefrom while being pelletized. Regarding the obtained polycarbonateresin (A1), Mw was 33000, Tg was 115° C., residual phenol was 300 ppm,and residual DPC was 250 ppm.

(Synthesis Example 2: Production of Polycarbonate Resin (B1))

19.5 kg (44.5 mol) of 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene, 9.93kg (46.3 mol) of diphenyl carbonate and 2.2×10⁻² g (2.7×10⁻⁴ mol) ofsodium hydrogen carbonate were put into a 50 L reactor equipped with astirrer and a distillation apparatus, and it was heated to 215° C. over1 hour under nitrogen atmosphere (760 mmHg) and stirred. After that, thepressure reducing degree was adjusted to 150 mmHg over 15 minutes, andconditions were kept at 215° C. and 15 mmHg for 20 minutes to perform atransesterification reaction. Further, the temperature was increased to240° C. at a rate of 37.5° C./hr, and conditions were kept at 240° C.and 150 mmHg for 10 minutes. After that, the pressure reducing degreewas adjusted to 120 mmHg over 10 minutes, and conditions were kept at240° C. and 120 mmHg for 70 minutes. After that, the pressure reducingdegree was adjusted to 100 mmHg over 10 minutes, and conditions werekept at 240° C. and 100 mmHg for 10 minutes. Further, the pressurereducing degree was adjusted to 1 mmHg or less over 40 minutes, andstirring was performed under conditions of 240° C. and 1 mmHg or lessfor 10 minutes to perform a polymerization reaction. After the reactionwas completed, nitrogen was blown into the reactor to increase thepressure, and a polycarbonate resin produced was taken out therefromwhile being pelletized. Regarding the obtained polycarbonate resin (B1),Mw was 25000, Tg was 146° C., residual phenol was 250 ppm, and residualDPC was 230 ppm.

Example 13

0.44 kg of the pellet of the polycarbonate resin (A1) produced inSynthesis Example 1, 4.57 kg of the pellet of the polycarbonate resin(B1) produced in Synthesis Example 2, 7.5 g of pentaerythritoltetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and 7.5 g ofmonoglyceride stearate were mixed together with shaking well, and themixture was kneaded and pelletized at 260° C. using an extruder toobtain 3.3 kg of a blend pellet. Tg of the pellet was 142° C., and noinflection point was found. The content of phenol in the pellet was 450ppm. Further, Mw of the pellet was 25,000. The pellet wasinjection-molded to obtain a circular plate having a diameter of 50 mmand a thickness of 3 mm. The circular plate was transparent. Theevaluation results are shown in Table 7.

Example 14

1.34 kg of the pellet of the polycarbonate resin (A1) produced inSynthesis Example 1, 3.66 kg of the pellet of the polycarbonate resin(B1) produced in Synthesis Example 2, 7.5 g of pentaerythritoltetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and 7.5 g ofmonoglyceride stearate were mixed together with shaking well, and themixture was kneaded and pelletized at 260° C. using an extruder toobtain 3.2 kg of a blend pellet. Tg of the pellet was 136° C., and noinflection point was found. Further, Mw of the pellet was 26,000. Thecontent of phenol in the pellet was 350 ppm. The pellet wasinjection-molded to obtain a circular plate having a diameter of 50 mmand a thickness of 3 mm. The circular plate was transparent. Theevaluation results are shown in Table 7.

Example 15

2.30 kg of the pellet of the polycarbonate resin (A1) produced inSynthesis Example 1, 2.70 kg of the pellet of the polycarbonate resin(B1) produced in Synthesis Example 2, 7.5 g of pentaerythritoltetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and 7.5 g ofmonoglyceride stearate were mixed together with shaking well, and themixture was kneaded and pelletized at 260° C. using an extruder toobtain 3.2 kg of a blend pellet. Tg of the pellet was 128° C., and noinflection point was found. Further, Mw of the pellet was 27,000. Thecontent of phenol in the pellet was 370 ppm. The pellet wasinjection-molded to obtain a circular plate having a diameter of 50 mmand a thickness of 3 mm. The circular plate was transparent. Theevaluation results are shown in Table 7.

Example 16

3.33 kg of the pellet of the polycarbonate resin (A1) produced inSynthesis Example 1, 1.67 kg of the pellet of the polycarbonate resin(B1) produced in Synthesis Example 2, 7.5 g of pentaerythritoltetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and 7.5 g ofmonoglyceride stearate were mixed together with shaking well, and themixture was kneaded and pelletized at 260° C. using an extruder toobtain 3.3 kg of a blend pellet. Tg of the pellet was 123° C., and noinflection point was found. Further, Mw of the pellet was 29,000. Thecontent of phenol in the pellet was 450 ppm. The pellet wasinjection-molded to obtain a circular plate having a diameter of 50 mmand a thickness of 3 mm. The circular plate was transparent. Theevaluation results are shown in Table 7.

Example 17

4.43 kg of the pellet of the polycarbonate resin (A1) produced inSynthesis Example 1, 0.58 kg of the pellet of the polycarbonate resin(B1) produced in Synthesis Example 2, 7.5 g of pentaerythritoltetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and 7.5 g ofmonoglyceride laurate were mixed together with shaking well, and themixture was kneaded and pelletized at 260° C. using an extruder toobtain 3.3 kg of a blend pellet. Tg of the pellet was 117° C., and noinflection point was found. Further, Mw of the pellet was 31,000. Thecontent of phenol in the pellet was 380 ppm. The pellet wasinjection-molded to obtain a circular plate having a diameter of 50 mmand a thickness of 3 mm. The circular plate was transparent. Theevaluation results are shown in Table 7.

Comparative Example 4

A pellet of a polycarbonate resin made of bisphenol A type polycarbonateresin “Iupilon H-4000” (trade name, manufactured by MitsubishiEngineering-Plastics Corporation, Mw: 33000) was injection-molded toobtain a circular plate having a diameter of 50 mm and a thickness of 3mm. The circular plate was transparent. The evaluation results are shownin Table 7.

Comparative Example 5

The pellet produced in Synthesis Example 1 was injection-molded toobtain a circular plate having a diameter of 50 mm and a thickness of 3mm. The circular plate was transparent. The evaluation results are shownin Table 7.

Comparative Example 6

The pellet produced in Synthesis Example 2 was injection-molded toobtain a circular plate having a diameter of 50 mm and a thickness of 3mm. The circular plate was transparent. The evaluation results are shownin Table 7.

TABLE 7 Comparative Comparative Comparative Resin composition Example 13Example 14 Example 15 Example 16 Example 17 Example 4 Example 5 Example6 Parts by weight of resin (A1) 8.8 26.8 46 66.6 88.4 — 100 — Parts byweight of resin (B1) 91.2 73.2 54 33.4 11.6 — — 100 Parts by weight ofH4000 — — — — — 100 — — Tg (° C.) 142 136 128 123 117 146 115 146Refractive index nD 1.642 1.646 1.652 1.659 1.665 1.586 1.668 1.639 Abbenumber ν 23 22 21 20 19 30 19 24 Optical distortion B A A A A C B B2. Polyester Resin<Methods for Evaluating Polyester Resins>

Methods for evaluating polyester resins used in the Examples are asdescribed below.

(1) Polystyrene equivalent weight-average molecular weight (Mw): Usinggel filtration chromatograph (GPC) and chloroform as a developingsolvent, a calibration curve was produced using a standard polystyrenehaving an already-known molecular weight (molecular weightdistribution=1). Based on this calibration curve, Mw was calculated fromthe GPC retention time.[Measurement Conditions]Apparatus: HLC-8320GPC manufactured by Tosoh CorporationColumn:

Guard column: TSKguardcolumn SuperMPHZ-M×1

Analysis column: TSKgel SuperMultiporeHZ-M×3

Solvent: tetrahydrofuran

Injection amount: 10 μL

Sample concentration: 0.2 w/v % tetrahydrofuran solution

Flow rate of solvent: 0.35 ml/min

Measurement temperature: 40° C.

Detector: RI

(2) Refractive Index, Abbe Number

The polyester resin was dissolved in methylene chloride to prepare aresin solution in which the solid component concentration was 5.3 wt %.This resin solution was poured into a mold for the production of a castfilm, and released and dried after volatilization of methylene chloride,thereby preparing a cast film having a thickness of 0.1 mm. Therefractive index (nD) and the Abbe number (v) of the cast film wereevaluated.

The refractive index was measured according to the method of JIS-K-7142using a refractometer manufactured by Atago Co., Ltd. (25° C.,wavelength: 589 nm). Regarding the Abbe number, refractive indexes weremeasured at wavelengths of 486 nm, 589 nm and 656 nm at 25° C. using arefractometer manufactured by Atago Co., Ltd., and the Abbe number wascalculated using the below-described formula:v=(nD−1)/(nF−nC)

nD: refractive index at a wavelength of 589 nm

nC: refractive index at a wavelength of 656 nm

nF: refractive index at a wavelength of 486 nm

(3) Glass transition temperature (Tg): It was measured using adifferential scanning calorimeter (DSC) (measurement apparatus: DSC7000Xmanufactured by Hitachi High-Tech Science Corporation).

Example 18

1.00 mol of dimethyl terephthalate (hereinafter referred to as “DMT”),2.20 mol of ethylene glycol, 0.10 mol of9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene (hereinafter referred to as“BPEF”) and 0.81 mol of 2,2′-bis(2-hydroxyethoxy)-1,1′-binaphthalene(hereinafter referred to as “BHEBN”) were added to a glass flaskequipped with a heating apparatus, a stirring blade, a partialcondenser, a trap, a thermometer and a nitrogen gas introduction tube.The mixture was gradually heated and melted with stirring under nitrogenatmosphere in the presence of zinc acetate dihydrate in an amount of0.023 mol % relative to the dicarboxylic acid component to perform anesterification reaction. After the reaction conversion rate of thedicarboxylic acid component became 90% or more, germanium oxide in anamount of 0.14 mol % and triethyl phosphate in an amount of 0.12 mol %relative to 100 mol % of the dicarboxylic acid component were added. Thetemperature was gradually increased and the pressure was graduallyreduced, ethylene glycol was removed while reducing the pressure, andfinally, polycondensation was performed at 250 to 280° C. and 0.1 kPa orless. After that, the content was taken out from the reactor, and acopolymerized polyester resin having a fluorene skeleton was obtained.

The polystyrene equivalent weight-average molecular weight of theobtained polyester resin was 42,000. Evaluation of physical propertiesis shown in Table 8.

Example 19

The operation was carried out in a manner similar to that in Example 1,except that the amounts of BPEF and BHEBN were changed to 0.27 mol and0.63 mol, respectively, and that DMT was changed to dimethyl2,6-naphthalenedicarboxylate (hereinafter abbreviated as “NDCM”). As aresult, a polyester copolymer having a weight average molecular weightof 40,500 was obtained. Evaluation of physical properties is shown inTable 8.

Comparative Examples 7-10

A transesterification reaction and a polycondensation reaction wereperformed using the same apparatus and reaction conditions as those inExample 18 above, except that the raw materials and feed amounts werechanged to those described in Table 8, and a copolymerized polyesterresin was obtained. The results of evaluation of physical properties ofthe obtained resin are shown in Table 8.

TABLE 8 Copolymerization composition ratio Physical propertiesDicarboxylic acid component Dihydroxy component Refractive (molar ratio)(molar ratio) index (d line/ DMT DMI DMN FDPT NDCM EG BPEF BHEBN Tg (°C.) 25° C.) Abbe number Example 18 1.00 0.10 0.09 0.81 120 1.658 20Example 19 1.00 0.10 0.27 0.63 124 1.652 20 Comparative 1.00 0.20 0.80122 1.634 23 Example 7 Comparative 0.50 0.50 0.15 0.85 137 1.645 22Example 8 Comparative 0.75 0.25 0.15 0.85 151 1.652 21 Example 9Comparative 0.50 0.50 0.10 0.90 150 1.650 21 Example 10 DMT: dimethylterephthalate DMI: dimethyl isophthalate DMN: dimethyl2,6-naphthalenedicarboxylate FDPT: 9,9-di(ethylt-butoxycarboxylate)fluorene (9,9-di(carboxyethyl)fluorene or di-t-butylester of fluorene-9,9-dipropionic acid NDCM: dimethylnaphthalenecarboxylate EG: ethylene glycol BPEF:9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene BHEBN:2,2′-bis(2-hydroxyethoxy)-1,1′-binaphthalene3. Polyester Carbonate Resin<Methods for Evaluating Polyester Carbonate Resins>

Measurement values of polyester carbonate resins in the Examples weremeasured using the below-described methods and apparatuses.

1) Average molecular weights: Using gel permeation chromatograph (GPC)Shodex GPC-101 manufactured by Showa Denko K.K. and tetrahydrofuran as adeveloping solvent, a calibration curve was produced using a standardpolystyrene having an already-known molecular weight (molecular weightdistribution=1). Based on this calibration curve, the number-averagemolecular weight (Mn) and the weight-average molecular weight (Mw) werecalculated from the GPC retention time.[Measurement Conditions]Apparatus: HLC-8320GPC manufactured by Tosoh CorporationColumn:

Guard column: TSKguardcolumn SuperMPHZ-M×1

Analysis column: TSKgel SuperMultiporeHZ-M×3

Solvent: tetrahydrofuran

Injection amount: 10 μL

Sample concentration: 0.2 w/v % tetrahydrofuran solution

Flow rate of solvent: 0.35 ml/min

Measurement temperature: 40° C.

Detector: RI

2) Glass transition temperature (Tg): 0.008 g of the produced resin wasweighed and Tg was measured at a temperature raising rate of 10° C./minusing a simultaneous thermogravimetric analyzer DSC220 manufactured bySeiko Instruments Inc.

3) Refractive index (nD): The polyester carbonate resin was press-moldedto obtain a circular plate having a diameter of 40 mm and a thickness of3 mm, and the refractive index of the circular plate was measured at 25°C. using a refractometer (KPR-200) manufactured by Shimadzu DeviceCorporation (wavelength: 589 nm).4) Abbe number (v): The polyester carbonate resin was press-molded toobtain a circular plate having a diameter of 40 mm and a thickness of 3mm, and refractive indexes were measured at wavelengths of 486 nm, 589nm and 656 nm using a refractometer (KPR-200) manufactured by ShimadzuDevice Corporation. Further, the Abbe number was calculated using thebelow-described formula:v=(nD−1)/(nF−nC)

nD: refractive index at a wavelength of 589 nm

nC: refractive index at a wavelength of 656 nm

nF: refractive index at a wavelength of 486 nm

5) Color phase of solution: 6 g of the produced resin was dissolved in60 ml of dichloromethane, and the L value (brightness) was measuredusing a quartz glass cell having an optical path length of 5.0 cm. As acolor-difference meter, Spectro Color Meter SE2000 manufactured byNippon Denshoku Industries Co., Ltd. was used.

Example 20

17.3 g (0.046 mol) of 2,2′-bis(2-hydroxyethoxy)-1,1′-binaphthalene(hereinafter sometimes abbreviated as “BHEBN”), 25.27 g (0.058 mol) of9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene (hereinafter sometimesabbreviated as “BPEF”), 19.94 g (0.093 mol) of diphenyl carbonate(hereinafter sometimes abbreviated as “DPC”) and 2.239 g (0.012 mol) ofdimethyl terephthalate (hereinafter sometimes abbreviated as “DMT”) wereput into a 300 ml four-neck flask equipped with a stirrer and adistillation apparatus. After pressure reduction and nitrogen chargingwere repeated 5 times, it was heated at 180° C. under nitrogenatmosphere (760 mmHg). 10 minutes after the start of heating, completedissolution of the raw materials was confirmed. After that, stirring wasperformed for 10 minutes under the same conditions. After that, therotational speed was increased to 200 rpm, the pressure was reduced to200 mmHg at a rate of 28 mmHg/min, and the temperature was increased to260° C. at a rate of 60° C./hr. During this, the start of distillationof by-produced phenol was confirmed. After the pressure reached 200 mmHgand the temperature reached 260° C., the pressure was reduced at 10mmHg/min, and 20 minutes after the pressure reached 0 mmHg, the reactionwas completed. Finally, nitrogen was blown into the reactor to adjustthe pressure to ordinary pressure, and a polyester carbonate resinproduced was taken out therefrom.

Example 21

17.3 g (0.046 mol) of BHEBN, 25.27 g (0.058 mol) of BPEF, 19.94 g (0.093mol) of DPC and 2.239 g (0.012 mol) of DMT were put into a 300 mlfour-neck flask equipped with a stirrer and a distillation apparatus.After pressure reduction and nitrogen charging were repeated 5 times, itwas heated at 180° C. under nitrogen atmosphere (760 mmHg). 10 minutesafter the start of heating, complete dissolution of the raw materialswas confirmed. After that, stirring was performed for 10 minutes underthe same conditions. After that, the rotational speed was increased to200 rpm, the pressure was reduced to 200 mmHg at a rate of 28 mmHg/min,and the temperature was increased to 240° C. at a rate of 60° C./hr.During this, the start of distillation of by-produced phenol wasconfirmed. After the pressure reached 200 mmHg and the temperaturereached 240° C., the pressure was reduced at 10 mmHg/min, and 40 minutesafter the pressure reached 0.8 mmHg, the reaction was completed.Finally, nitrogen was blown into the reactor to adjust the pressure toordinary pressure, and a polyester carbonate resin produced was takenout therefrom.

Example 22

35.64 g (0.095 mol) of BHEBN, 4.615 g (0.011 mol) of BPEF, 20.00 g(0.093 mol) of DPC and 2.557 g (0.013 mol) of DMT were put into a 300 mlfour-neck flask equipped with a stirrer and a distillation apparatus.After pressure reduction and nitrogen charging were repeated 5 times, itwas heated at 180° C. under nitrogen atmosphere (760 mmHg). 10 minutesafter the start of heating, complete dissolution of the raw materialswas confirmed. After that, stirring was performed for 10 minutes underthe same conditions. After that, the pressure was reduced to 200 mmHg ata rate of 28 mmHg/min, and the temperature was increased to 250° C. at arate of 60° C./hr. During this, the start of distillation of by-producedphenol was confirmed. Finally, nitrogen was blown into the reactor toadjust the pressure to ordinary pressure, and a polyester carbonateresin produced was taken out therefrom.

Example 23

3.928 g (0.011 mol) of BHEBN, 41.95 g (0.096 mol) of BPEF, 20.34 g(0.095 mol) of DPC and 2.287 g (0.012 mol) of DMT were put into a 300 mlfour-neck flask equipped with a stirrer and a distillation apparatus.After pressure reduction and nitrogen charging were repeated 5 times, itwas heated at 180° C. under nitrogen atmosphere (760 mmHg). 10 minutesafter the start of heating, complete dissolution of the raw materialswas confirmed. After that, stirring was performed for 10 minutes underthe same conditions. After that, the rotational speed was increased to200 rpm, the pressure was reduced to 200 mmHg at a rate of 28 mmHg/min,and the temperature was increased to 260° C. at a rate of 60° C./hr.During this, the start of distillation of by-produced phenol wasconfirmed. After the pressure reached 200 mmHg and the temperaturereached 260° C., the pressure was reduced at 1.6 mmHg/min. Finally, 20minutes after the pressure reached 0.8 mmHg, the reaction was completed.Nitrogen was blown into the reactor to adjust the pressure to ordinarypressure, and a polyester carbonate resin produced was taken outtherefrom.

Example 24

10.92 g (0.029 mol) of BHEBN, 33.41 g (0.076 mol) of BPEF, 20.10 g(0.093 mol) of DPC and 2.289 g (0.0118 mol) of DMT were put into a 300ml four-neck flask equipped with a stirrer and a distillation apparatus.After pressure reduction and nitrogen charging were repeated 5 times, itwas heated at 180° C. under nitrogen atmosphere (760 mmHg). 10 minutesafter the start of heating, complete dissolution of the raw materialswas confirmed. After that, stirring was performed for 10 minutes underthe same conditions. After that, the rotational speed was increased to200 rpm, the pressure was reduced to 200 mmHg at a rate of 4.6 mmHg/min,and the temperature was increased to 260° C. at a rate of 60° C./hr.During this, the start of distillation of by-produced phenol wasconfirmed. After the pressure reached 200 mmHg and the temperaturereached 260° C., the pressure was reduced at 3.3 mmHg/min. 60 minutesafter the pressure reached 0.8 mmHg, the reaction was completed.Finally, nitrogen was blown into the reactor to adjust the pressure toordinary pressure, and a polyester carbonate resin produced was takenout therefrom.

Example 25

23.96 g (0.064 mol) of BHEBN, 17.61 g (0.040 mol) of BPEF, 19.84 g(0.093 mol) of DPC and 2.289 g (0.012 mol) of DMT were put into a 300 mlfour-neck flask equipped with a stirrer and a distillation apparatus.After pressure reduction and nitrogen charging were repeated 5 times, itwas heated at 180° C. under nitrogen atmosphere (760 mmHg). 10 minutesafter the start of heating, complete dissolution of the raw materialswas confirmed. After that, stirring was performed for 10 minutes underthe same conditions. After that, the rotational speed was increased to200 rpm, the pressure was reduced to 200 mmHg at a rate of 28 mmHg/min,and the temperature was increased to 260° C. at a rate of 60° C./hr.During this, the start of distillation of by-produced phenol wasconfirmed. After the pressure reached 200 mmHg and the temperaturereached 260° C., the pressure was reduced at 3.3 mmHg/min. 30 minutesafter the pressure reached 0.8 mmHg, the reaction was completed.Finally, nitrogen was blown into the reactor to adjust the pressure toordinary pressure, and a polyester carbonate resin produced was takenout therefrom.

Comparative Example 11

12.94 g (0.035 mol) of BHBN, 24.77 g (0.057 mol) of BPEF, 20.09 g (0.094mol) of DPC and 2.187 g (0.0113 mol) of DMT were put into a 300 mlfour-neck flask equipped with a stirrer and a distillation apparatus.After pressure reduction and nitrogen charging were repeated 5 times, itwas heated at 180° C. under nitrogen atmosphere (760 mmHg). 10 minutesafter the start of heating, complete dissolution of the raw materialswas confirmed. After that, stirring was performed for 10 minutes underthe same conditions. After that, the rotational speed was increased to200 rpm, the pressure was reduced to 200 mmHg at a rate of 28 mmHg/min,and the temperature was increased to 260° C. at a rate of 60° C./hr.During this, the start of distillation of by-produced phenol wasconfirmed. After the pressure reached 200 mmHg and the temperaturereached 260° C., the pressure was reduced at 10 mmHg/min. After thepressure reached 0.8 mmHg, the reaction was completed. Nitrogen wasblown into the reactor to adjust the pressure to ordinary pressure, anda polyester carbonate resin produced was taken out therefrom.

Comparative Example 12

26.80 g (0.072 mol) of BHBN, 4.544 g (0.0104 mol) of BPEF, 19.98 g(0.093 mol) of DPC and 2.236 g (0.0115 mol) of DMT were put into a 300ml four-neck flask equipped with a stirrer and a distillation apparatus.After pressure reduction and nitrogen charging were repeated 5 times, itwas heated at 180° C. under nitrogen atmosphere (760 mmHg). 10 minutesafter the start of heating, complete dissolution of the raw materialswas confirmed. After that, stirring was performed for 10 minutes underthe same conditions. The rotational speed was increased to 200 rpm, thepressure was reduced to 200 mmHg at a rate of 28 mmHg/min, and thetemperature was increased to 260° C. at a rate of 60° C./hr. Duringthis, the start of distillation of by-produced phenol was confirmed.After the pressure reached 200 mmHg and the temperature reached 260° C.,the pressure was reduced at 10 mmHg/min. After the pressure reached 0.8mmHg, the reaction was completed. Nitrogen was blown into the reactor toadjust the pressure to ordinary pressure, and a polyester carbonateresin produced was taken out therefrom.

Note that it was impossible to press-mold the resins of ComparativeExamples 11 and 12, and therefore the refractive index and the Abbenumber thereof were not measured.

TABLE 9 Copolymerization composition ratio Evaluation resultsDicarboxylic Refractive glass acid component Dihydroxy component index(d line/ Abbe Molecular transition (mol %) (mol %) 25° C.) number weighttemperature Brightness DMT BHEBN BHBN BPEF nD ν Mn Mw Tg (° C.) LExample 20 10 40 50 1.650 21 16600 33000 133 94.7 Example 21 10 40 501.653 21 12400 24200 134 95.1 Example 22 11 80 9 1.653 19 6800 12400 11895.2 Example 23 10 9 81 1.647 23 16800 37000 149 95.0 Example 24 10 2565 1.646 22 16900 37100 144 89.1 Example 25 10 55 35 1.650 21 1730040600 135 97.6 Comparative 10 40 50 — — 2600 3700 — 69.2 Example 11Comparative 10 81 9 — — 1400 1600 110 26.2 Example 12 DMT: dimethylterephthalate, BHEBN: 2,2′-bis(2-hydroxyethoxy)-1,1′-binaphthalene BHBN:2,2′-bis(2-hydroxy)-1,1′-binaphthalene BPEF:9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene

The invention claimed is:
 1. A polyester carbonate resin, comprising: astructural unit derived from a compound represented by general formula(1) below:

wherein X represents a C₂ alkylene group; a structural unit derived froma compound represented by general formula (2a) below:

wherein R¹ and R² each independently represent a hydrogen atom, a C₁₋₂₀alkyl group, a C₁₋₂₀ alkoxyl group, a C₅₋₂₀ cycloalkyl group, a C₅₋₂₀cycloalkoxyl group, a C₆₋₂₀ aryl group or a C₆₋₂₀ aryloxy group; astructural unit derived from a terephthalic acid or an ester thereof; astructural unit derived from a carbonic acid diester; and wherein thepolyester carbonate resin has a polystyrene equivalent weight-averagemolecular weight (Mw) of 14,000 to 100,000.
 2. The polyester carbonateresin according to claim 1, wherein R¹ and R² are hydrogen atoms.
 3. Thepolyester carbonate resin according to claim 1, wherein in structuralunits derived from a dihydroxy compound in the polyester carbonateresin, the ratio of the structural unit derived from the compoundrepresented by general formula (1) is 9 to 80 mol % and the ratio of thestructural unit derived from the compound represented by general formula(2a) is 9 to 81 mol %.
 4. The polyester carbonate resin according toclaim 1, which has a refractive index of 1.645 to 1.660.
 5. An opticalmember comprising the polyester carbonate resin according to claim
 1. 6.The optical member according to claim 5, which is an optical lens of asingle-lens reflex camera, a digital still camera, a video camera, acellular phone with a camera, a disposable camera, a telescope,binoculars, a microscope or a projector.